diff --git a/analyzer/src/main/kotlin/managers/GoDep.kt b/analyzer/src/main/kotlin/managers/GoDep.kt
index a979637c330db..1575872c68bab 100644
--- a/analyzer/src/main/kotlin/managers/GoDep.kt
+++ b/analyzer/src/main/kotlin/managers/GoDep.kt
@@ -116,7 +116,7 @@ class GoDep(
 
         val projects = parseProjects(workingDir, gopath)
         val packages = mutableSetOf<Package>()
-        val packageRefs = mutableListOf<PackageReference>()
+        val packageRefs = mutableSetOf<PackageReference>()
 
         for (project in projects) {
             // parseProjects() made sure that all entries contain these keys
@@ -156,7 +156,7 @@ class GoDep(
             packageRefs += pkg.toReference(linkage = PackageLinkage.STATIC, issues = issues)
         }
 
-        val scope = Scope("default", packageRefs.toSortedSet())
+        val scope = Scope("default", packageRefs)
 
         val projectName = runCatching {
             val uri = URI(projectVcs.url)
diff --git a/analyzer/src/main/kotlin/managers/utils/Graph.kt b/analyzer/src/main/kotlin/managers/utils/Graph.kt
index ef792224e8fdb..a147c0cc70d21 100644
--- a/analyzer/src/main/kotlin/managers/utils/Graph.kt
+++ b/analyzer/src/main/kotlin/managers/utils/Graph.kt
@@ -20,7 +20,6 @@
 package org.ossreviewtoolkit.analyzer.managers.utils
 
 import java.util.LinkedList
-import java.util.SortedSet
 
 import org.apache.logging.log4j.kotlin.Logging
 
@@ -122,9 +121,9 @@ internal class Graph private constructor(private val nodeMap: MutableMap<Identif
      * Convert this [Graph] to a set of [PackageReference]s that spawn the dependency trees of the direct dependencies
      * of the given [root] package. The graph must not contain any cycles, so [breakCycles] should be called before.
      */
-    fun toPackageReferenceForest(root: Identifier): SortedSet<PackageReference> {
+    fun toPackageReferenceForest(root: Identifier): Set<PackageReference> {
         fun getPackageReference(id: Identifier): PackageReference {
-            val dependencies = nodeMap.getValue(id).mapTo(sortedSetOf()) {
+            val dependencies = nodeMap.getValue(id).mapTo(mutableSetOf()) {
                 getPackageReference(it)
             }
 
@@ -135,7 +134,7 @@ internal class Graph private constructor(private val nodeMap: MutableMap<Identif
             )
         }
 
-        return dependencies(root).mapTo(sortedSetOf()) { getPackageReference(it) }
+        return dependencies(root).mapTo(mutableSetOf()) { getPackageReference(it) }
     }
 
     /**
diff --git a/analyzer/src/test/kotlin/AnalyzerResultBuilderTest.kt b/analyzer/src/test/kotlin/AnalyzerResultBuilderTest.kt
index 552cae41820e3..2580673211ab2 100644
--- a/analyzer/src/test/kotlin/AnalyzerResultBuilderTest.kt
+++ b/analyzer/src/test/kotlin/AnalyzerResultBuilderTest.kt
@@ -66,11 +66,11 @@ class AnalyzerResultBuilderTest : WordSpec() {
 
     private val pkgRef1 = package1.toReference(issues = listOf(issue1))
     private val pkgRef2 = package2.toReference(
-        dependencies = sortedSetOf(package3.toReference(issues = listOf(issue2)))
+        dependencies = setOf(package3.toReference(issues = listOf(issue2)))
     )
 
-    private val scope1 = Scope("scope-1", sortedSetOf(pkgRef1))
-    private val scope2 = Scope("scope-2", sortedSetOf(pkgRef2))
+    private val scope1 = Scope("scope-1", setOf(pkgRef1))
+    private val scope2 = Scope("scope-2", setOf(pkgRef2))
 
     private val project1 = Project.EMPTY.copy(
         id = Identifier("type-1", "namespace-1", "project-1", "version-1"),
@@ -339,11 +339,11 @@ class AnalyzerResultBuilderTest : WordSpec() {
 
                 val scope = Scope(
                     name = "scope",
-                    dependencies = sortedSetOf(
+                    dependencies = setOf(
                         packageManagerDependency,
                         PackageReference(
                             id = pkgRef1.id,
-                            dependencies = sortedSetOf(packageManagerDependency)
+                            dependencies = setOf(packageManagerDependency)
                         )
                     )
                 )
@@ -370,19 +370,19 @@ class AnalyzerResultBuilderTest : WordSpec() {
                         project.scopes shouldContainExactly sortedSetOf(
                             Scope(
                                 name = "scope",
-                                dependencies = sortedSetOf(
+                                dependencies = setOf(
                                     PackageReference(
                                         id = project1.id,
-                                        dependencies = sortedSetOf(
+                                        dependencies = setOf(
                                             PackageReference(id = package1.id)
                                         )
                                     ),
                                     PackageReference(
                                         id = package1.id,
-                                        dependencies = sortedSetOf(
+                                        dependencies = setOf(
                                             PackageReference(
                                                 id = project1.id,
-                                                dependencies = sortedSetOf(
+                                                dependencies = setOf(
                                                     PackageReference(id = package1.id)
                                                 )
                                             )
diff --git a/evaluator/src/test/kotlin/TestData.kt b/evaluator/src/test/kotlin/TestData.kt
index 9a3162cd1857c..dbd79fe360b2a 100644
--- a/evaluator/src/test/kotlin/TestData.kt
+++ b/evaluator/src/test/kotlin/TestData.kt
@@ -137,7 +137,7 @@ val allPackages = setOf(
 
 val scopeExcluded = Scope(
     name = "compile",
-    dependencies = sortedSetOf(
+    dependencies = setOf(
         packageExcluded.toReference()
     )
 )
@@ -153,11 +153,11 @@ val packageRefStaticallyLinked = packageStaticallyLinked.toReference(PackageLink
 
 val scopeIncluded = Scope(
     name = "compile",
-    dependencies = sortedSetOf(
+    dependencies = setOf(
         packageWithoutLicense.toReference(),
         packageWithNotPresentLicense.toReference(),
         packageWithOnlyConcludedLicense.toReference(),
-        packageWithOnlyDeclaredLicense.toReference(dependencies = sortedSetOf(packageDependency.toReference())),
+        packageWithOnlyDeclaredLicense.toReference(dependencies = setOf(packageDependency.toReference())),
         packageWithConcludedAndDeclaredLicense.toReference(),
         packageRefDynamicallyLinked,
         packageRefStaticallyLinked,
diff --git a/model/src/main/kotlin/DependencyGraph.kt b/model/src/main/kotlin/DependencyGraph.kt
index 520da629de0fa..7db82bb5470d3 100644
--- a/model/src/main/kotlin/DependencyGraph.kt
+++ b/model/src/main/kotlin/DependencyGraph.kt
@@ -170,7 +170,7 @@ data class DependencyGraph(
      */
     private fun createScopesFor(map: Map<String, List<RootDependencyIndex>>, unqualify: Boolean): Set<Scope> =
         map.mapTo(mutableSetOf()) { entry ->
-            val dependencies = entry.value.mapTo(sortedSetOf()) { index ->
+            val dependencies = entry.value.mapTo(mutableSetOf()) { index ->
                 referenceMapping[index.toKey()] ?: error("Could not resolve dependency index $index.")
             }
 
@@ -201,7 +201,7 @@ data class DependencyGraph(
     ): PackageReference {
         val indexKey = RootDependencyIndex.generateKey(node.pkg, node.fragment)
         return refMapping.getOrPut(indexKey) {
-            val refDependencies = dependencies[node].orEmpty().mapTo(sortedSetOf()) {
+            val refDependencies = dependencies[node].orEmpty().mapTo(mutableSetOf()) {
                 constructReferenceTree(it, refMapping)
             }
 
diff --git a/model/src/main/kotlin/Package.kt b/model/src/main/kotlin/Package.kt
index 60a0585a14e65..f6a4f28ef0d03 100644
--- a/model/src/main/kotlin/Package.kt
+++ b/model/src/main/kotlin/Package.kt
@@ -22,8 +22,6 @@ package org.ossreviewtoolkit.model
 import com.fasterxml.jackson.annotation.JsonInclude
 import com.fasterxml.jackson.databind.annotation.JsonSerialize
 
-import java.util.SortedSet
-
 import org.ossreviewtoolkit.model.utils.toPurl
 import org.ossreviewtoolkit.utils.common.StringSortedSetConverter
 import org.ossreviewtoolkit.utils.ort.DeclaredLicenseProcessor
@@ -186,7 +184,7 @@ data class Package(
      */
     fun toReference(
         linkage: PackageLinkage? = null,
-        dependencies: SortedSet<PackageReference>? = null,
+        dependencies: Set<PackageReference>? = null,
         issues: List<Issue>? = null
     ): PackageReference {
         var ref = PackageReference(id)
diff --git a/model/src/main/kotlin/PackageReference.kt b/model/src/main/kotlin/PackageReference.kt
index e819acc36c292..a69dd1355f306 100644
--- a/model/src/main/kotlin/PackageReference.kt
+++ b/model/src/main/kotlin/PackageReference.kt
@@ -20,12 +20,13 @@
 package org.ossreviewtoolkit.model
 
 import com.fasterxml.jackson.annotation.JsonInclude
+import com.fasterxml.jackson.databind.annotation.JsonSerialize
 
 import java.util.Deque
 import java.util.LinkedList
-import java.util.SortedSet
 
 import org.ossreviewtoolkit.model.utils.PackageLinkageValueFilter
+import org.ossreviewtoolkit.model.utils.PackageReferenceSortedSetConverter
 
 /**
  * A human-readable reference to a software [Package]. Each package reference itself refers to other package
@@ -51,7 +52,8 @@ data class PackageReference(
      * The set of [references to packages][PackageReference] this package depends on. Note that this list depends on the
      * [scope][Scope] in which this package is referenced.
      */
-    val dependencies: SortedSet<PackageReference> = sortedSetOf(),
+    @JsonSerialize(converter = PackageReferenceSortedSetConverter::class)
+    val dependencies: Set<PackageReference> = emptySet(),
 
     /**
      * A list of [Issue]s that occurred handling this [PackageReference].
@@ -116,10 +118,10 @@ data class PackageReference(
      * return the modified [PackageReference]. The tree is traversed depth-first (post-order).
      */
     fun traverse(transform: (PackageReference) -> PackageReference): PackageReference {
-        val transformedDependencies = dependencies.map {
+        val transformedDependencies = dependencies.mapTo(mutableSetOf()) {
             it.traverse(transform)
         }
-        return transform(copy(dependencies = transformedDependencies.toSortedSet()))
+        return transform(copy(dependencies = transformedDependencies))
     }
 
     override fun <T> visitDependencies(block: (Sequence<DependencyNode>) -> T): T = block(dependencies.asSequence())
diff --git a/model/src/main/kotlin/Scope.kt b/model/src/main/kotlin/Scope.kt
index 666033a40089c..efe2761d13603 100644
--- a/model/src/main/kotlin/Scope.kt
+++ b/model/src/main/kotlin/Scope.kt
@@ -19,7 +19,9 @@
 
 package org.ossreviewtoolkit.model
 
-import java.util.SortedSet
+import com.fasterxml.jackson.databind.annotation.JsonSerialize
+
+import org.ossreviewtoolkit.model.utils.PackageReferenceSortedSetConverter
 
 /**
  * The scope class puts package dependencies into context.
@@ -39,7 +41,8 @@ data class Scope(
      * dependencies would not be test dependencies of the test dependencies, but compile dependencies of test
      * dependencies.
      */
-    val dependencies: SortedSet<PackageReference> = sortedSetOf()
+    @JsonSerialize(converter = PackageReferenceSortedSetConverter::class)
+    val dependencies: Set<PackageReference> = emptySet()
 ) : Comparable<Scope> {
     /**
      * Return the set of package [Identifier]s in this [Scope], up to and including a depth of [maxDepth] where counting
diff --git a/model/src/main/kotlin/utils/SortedSetConverters.kt b/model/src/main/kotlin/utils/SortedSetConverters.kt
index 75afb66300593..435410de67610 100644
--- a/model/src/main/kotlin/utils/SortedSetConverters.kt
+++ b/model/src/main/kotlin/utils/SortedSetConverters.kt
@@ -28,6 +28,7 @@ import java.util.SortedSet
 import org.ossreviewtoolkit.model.CopyrightFinding
 import org.ossreviewtoolkit.model.LicenseFinding
 import org.ossreviewtoolkit.model.Package
+import org.ossreviewtoolkit.model.PackageReference
 import org.ossreviewtoolkit.model.Project
 import org.ossreviewtoolkit.model.Scope
 
@@ -39,6 +40,10 @@ class LicenseFindingSortedSetConverter : StdConverter<Set<LicenseFinding>, Sorte
     override fun convert(value: Set<LicenseFinding>) = value.toSortedSet(LicenseFinding.COMPARATOR)
 }
 
+class PackageReferenceSortedSetConverter : StdConverter<Set<PackageReference>, SortedSet<PackageReference>>() {
+    override fun convert(value: Set<PackageReference>) = value.toSortedSet(compareBy { it.id })
+}
+
 class PackageSortedSetConverter : StdConverter<Set<Package>, SortedSet<Package>>() {
     override fun convert(value: Set<Package>) = value.toSortedSet(compareBy { it.id })
 }
diff --git a/model/src/test/kotlin/AbstractDependencyNavigatorTest.kt b/model/src/test/kotlin/AbstractDependencyNavigatorTest.kt
index 264956d1978b1..8d7be2b86d978 100644
--- a/model/src/test/kotlin/AbstractDependencyNavigatorTest.kt
+++ b/model/src/test/kotlin/AbstractDependencyNavigatorTest.kt
@@ -29,7 +29,7 @@ import io.kotest.matchers.collections.haveSize
 import io.kotest.matchers.collections.shouldContainExactlyInAnyOrder
 import io.kotest.matchers.maps.containExactly as containExactlyEntries
 import io.kotest.matchers.sequences.beEmpty as beEmptySequence
-import io.kotest.matchers.sequences.containExactly as containSequenceExactly
+import io.kotest.matchers.sequences.containAllInAnyOrder
 import io.kotest.matchers.should
 import io.kotest.matchers.shouldBe
 import io.kotest.matchers.shouldNot
@@ -72,7 +72,9 @@ abstract class AbstractDependencyNavigatorTest : WordSpec() {
 
         "directDependencies" should {
             "return the direct dependencies of a project" {
-                navigator.directDependencies(testProject, "test").map { it.id } should containSequenceExactly(
+                val scopeDependencies = navigator.directDependencies(testProject, "test").map { it.id }
+
+                scopeDependencies should containAllInAnyOrder(
                     Identifier("Maven:org.scalacheck:scalacheck_2.12:1.13.5"),
                     Identifier("Maven:org.scalatest:scalatest_2.12:3.0.4")
                 )
diff --git a/model/src/test/kotlin/CompatibilityDependencyNavigatorTest.kt b/model/src/test/kotlin/CompatibilityDependencyNavigatorTest.kt
index d603585159b84..51be3e3b99333 100644
--- a/model/src/test/kotlin/CompatibilityDependencyNavigatorTest.kt
+++ b/model/src/test/kotlin/CompatibilityDependencyNavigatorTest.kt
@@ -253,7 +253,8 @@ private fun createProject(
 /**
  * Create a [Scope] with the given [name] and a synthetic dependency.
  */
-private fun createScope(name: String): Scope {
-    val dependencies = sortedSetOf(PackageReference(Identifier.EMPTY.copy(name = "dep$name")))
-    return Scope(name, dependencies)
-}
+private fun createScope(name: String) =
+    Scope(
+        name = name,
+        dependencies = setOf(PackageReference(Identifier.EMPTY.copy(name = "dep$name")))
+    )
diff --git a/model/src/test/kotlin/DependencyGraphTest.kt b/model/src/test/kotlin/DependencyGraphTest.kt
index eb3a28b50339b..fb93ec5b223b4 100644
--- a/model/src/test/kotlin/DependencyGraphTest.kt
+++ b/model/src/test/kotlin/DependencyGraphTest.kt
@@ -242,7 +242,7 @@ private fun id(group: String, artifact: String, version: String): Identifier =
  */
 private fun scopeDependencies(scopes: Set<Scope>, name: String): String = buildString {
     scopes.find { it.name == name }?.let { scope ->
-        scope.dependencies.forEach { dumpDependencies(it) }
+        scope.dependencies.sorted().forEach { dumpDependencies(it) }
     }
 }
 
@@ -253,7 +253,7 @@ private fun StringBuilder.dumpDependencies(ref: PackageReference) {
     append(ref.id)
     if (ref.dependencies.isNotEmpty()) {
         append('<')
-        ref.dependencies.forEach { dumpDependencies(it) }
+        ref.dependencies.sorted().forEach { dumpDependencies(it) }
         append('>')
     }
 }
diff --git a/model/src/test/kotlin/DependencyTreeNavigatorTest.kt b/model/src/test/kotlin/DependencyTreeNavigatorTest.kt
index 03eb00326c866..2558ff1690cb5 100644
--- a/model/src/test/kotlin/DependencyTreeNavigatorTest.kt
+++ b/model/src/test/kotlin/DependencyTreeNavigatorTest.kt
@@ -35,7 +35,7 @@ class DependencyTreeNavigatorTest : AbstractDependencyNavigatorTest() {
                 // various corner cases.
                 val scope = Scope(
                     name = "test",
-                    dependencies = sortedSetOf(
+                    dependencies = setOf(
                         pkg("A"),
                         pkg("B") {
                             pkg("A")
@@ -92,7 +92,7 @@ class DependencyTreeNavigatorTest : AbstractDependencyNavigatorTest() {
             "return 1 if the scope contains only direct dependencies" {
                 val scope = Scope(
                     name = "test",
-                    dependencies = sortedSetOf(
+                    dependencies = setOf(
                         PackageReference(id = Identifier("a")),
                         PackageReference(id = Identifier("b"))
                     )
@@ -105,7 +105,7 @@ class DependencyTreeNavigatorTest : AbstractDependencyNavigatorTest() {
             "return 2 if the scope contains a tree of height 2" {
                 val scope = Scope(
                     name = "test",
-                    dependencies = sortedSetOf(
+                    dependencies = setOf(
                         pkg("a") {
                             pkg("a1")
                         }
@@ -119,7 +119,7 @@ class DependencyTreeNavigatorTest : AbstractDependencyNavigatorTest() {
             "return 3 if it contains a tree of height 3" {
                 val scope = Scope(
                     name = "test",
-                    dependencies = sortedSetOf(
+                    dependencies = setOf(
                         pkg("a") {
                             pkg("a1") {
                                 pkg("a11")
@@ -146,7 +146,7 @@ private const val RESULT_WITH_ISSUES_FILE = "src/test/assets/result-with-issues-
 
 private class PackageRefBuilder(id: String) {
     private val id = Identifier(id)
-    private val dependencies = sortedSetOf<PackageReference>()
+    private val dependencies = mutableSetOf<PackageReference>()
 
     fun pkg(id: String, block: PackageRefBuilder.() -> Unit = {}) {
         dependencies += PackageRefBuilder(id).apply { block() }.build()
diff --git a/model/src/test/kotlin/PackageReferenceTest.kt b/model/src/test/kotlin/PackageReferenceTest.kt
index 7112c6a4120a3..7ebf1a02e50ba 100644
--- a/model/src/test/kotlin/PackageReferenceTest.kt
+++ b/model/src/test/kotlin/PackageReferenceTest.kt
@@ -30,7 +30,7 @@ import io.kotest.matchers.string.endWith
 class PackageReferenceTest : WordSpec() {
     companion object {
         fun pkgRefFromIdStr(id: String, vararg dependencies: PackageReference) =
-            PackageReference(Identifier(id), dependencies = dependencies.toSortedSet())
+            PackageReference(Identifier(id), dependencies = dependencies.toSet())
     }
 
     private val node111 = pkgRefFromIdStr("::node1_1_1")
diff --git a/model/src/test/kotlin/config/ExcludesTest.kt b/model/src/test/kotlin/config/ExcludesTest.kt
index a6c0b47a460b9..6b48605a11de3 100644
--- a/model/src/test/kotlin/config/ExcludesTest.kt
+++ b/model/src/test/kotlin/config/ExcludesTest.kt
@@ -56,9 +56,9 @@ class ExcludesTest : WordSpec() {
     private val pathExclude3 = PathExclude("**/*.ext", PathExcludeReason.BUILD_TOOL_OF, "")
     private val pathExclude4 = PathExclude("**/file.ext", PathExcludeReason.BUILD_TOOL_OF, "")
 
-    private val scope1 = Scope("scope1", sortedSetOf(PackageReference(id)))
-    private val scope2 = Scope("scope2", sortedSetOf(PackageReference(id)))
-    private val scopeProject1 = Scope("scopeProject1", sortedSetOf(PackageReference(project1.id)))
+    private val scope1 = Scope("scope1", setOf(PackageReference(id)))
+    private val scope2 = Scope("scope2", setOf(PackageReference(id)))
+    private val scopeProject1 = Scope("scopeProject1", setOf(PackageReference(project1.id)))
 
     private val scopeExclude1 = ScopeExclude("scope1", ScopeExcludeReason.PROVIDED_DEPENDENCY_OF, "")
     private val scopeExclude2 = ScopeExclude("scope2", ScopeExcludeReason.PROVIDED_DEPENDENCY_OF, "")
diff --git a/model/src/test/kotlin/licenses/TestData.kt b/model/src/test/kotlin/licenses/TestData.kt
index 008574e54b92a..5da9ee53863b7 100644
--- a/model/src/test/kotlin/licenses/TestData.kt
+++ b/model/src/test/kotlin/licenses/TestData.kt
@@ -117,7 +117,7 @@ val allPackages = setOf(
 
 val scope = Scope(
     name = "compile",
-    dependencies = sortedSetOf(
+    dependencies = setOf(
         packageWithoutLicense.toReference(),
         packageWithConcludedLicense.toReference(),
         packageWithDeclaredLicense.toReference(),
diff --git a/model/src/test/kotlin/utils/DependencyGraphBuilderTest.kt b/model/src/test/kotlin/utils/DependencyGraphBuilderTest.kt
index 442a4f88bded9..e041ba6931759 100644
--- a/model/src/test/kotlin/utils/DependencyGraphBuilderTest.kt
+++ b/model/src/test/kotlin/utils/DependencyGraphBuilderTest.kt
@@ -121,10 +121,10 @@ class DependencyGraphBuilderTest : WordSpec({
                 "org.apache.commons",
                 "commons-configuration2",
                 "2.7",
-                dependencies = listOf(dep1, dep2)
+                dependencies = setOf(dep1, dep2)
             )
-            val dep4 = createDependency("org.apache.commons", "commons-csv", "1.5", dependencies = listOf(dep1))
-            val dep5 = createDependency("com.acme", "dep", "0.7", dependencies = listOf(dep3))
+            val dep4 = createDependency("org.apache.commons", "commons-csv", "1.5", dependencies = setOf(dep1))
+            val dep5 = createDependency("com.acme", "dep", "0.7", dependencies = setOf(dep3))
 
             val graph = createGraphBuilder()
                 .addDependency(scope1, dep1)
@@ -151,21 +151,21 @@ class DependencyGraphBuilderTest : WordSpec({
             val depLog = createDependency("commons-logging", "commons-logging", "1.2")
             val depConfig1 = createDependency(
                 "org.apache.commons", "commons-configuration2", "2.7",
-                dependencies = listOf(depLog, depLang)
+                dependencies = setOf(depLog, depLang)
             )
             val depConfig2 = createDependency(
                 "org.apache.commons", "commons-configuration2", "2.7",
-                dependencies = listOf(depLang)
+                dependencies = setOf(depLang)
             )
             val depAcme = createDependency(
                 "com.acme", "lib-full", "1.0",
-                dependencies = listOf(depConfig1, depLang)
+                dependencies = setOf(depConfig1, depLang)
             )
             val depAcmeExclude = createDependency(
                 "com.acme", "lib-exclude", "1.1",
-                dependencies = listOf(depConfig2)
+                dependencies = setOf(depConfig2)
             )
-            val depLib = createDependency("com.business", "lib", "1", dependencies = listOf(depConfig1, depAcmeExclude))
+            val depLib = createDependency("com.business", "lib", "1", dependencies = setOf(depConfig1, depAcmeExclude))
 
             val graph = createGraphBuilder()
                 .addDependency(scope, depAcme)
@@ -182,15 +182,15 @@ class DependencyGraphBuilderTest : WordSpec({
             val depLog = createDependency("commons-logging", "commons-logging", "1.2")
             val depConfig1 = createDependency(
                 "org.apache.commons", "commons-configuration2", "2.7",
-                dependencies = listOf(depLog, depLang)
+                dependencies = setOf(depLog, depLang)
             )
             val depConfig2 = createDependency(
                 "org.apache.commons", "commons-configuration2", "2.7",
-                dependencies = listOf(depLang)
+                dependencies = setOf(depLang)
             )
             val depAcmeExclude = createDependency(
                 "com.acme", "lib-exclude", "1.1",
-                dependencies = listOf(depConfig2)
+                dependencies = setOf(depConfig2)
             )
 
             val graph = createGraphBuilder()
@@ -207,8 +207,8 @@ class DependencyGraphBuilderTest : WordSpec({
         "deal with cycles in dependencies" {
             val scope = "CyclicScope"
             val depCyc1 = createDependency("org.cyclic", "cyclic", "77.7")
-            val depFoo = createDependency("org.foo", "foo", "1.2.0", dependencies = listOf(depCyc1))
-            val depCyc2 = createDependency("org.cyclic", "cyclic", "77.7", dependencies = listOf(depFoo))
+            val depFoo = createDependency("org.foo", "foo", "1.2.0", dependencies = setOf(depCyc1))
+            val depCyc2 = createDependency("org.cyclic", "cyclic", "77.7", dependencies = setOf(depFoo))
 
             val graph = createGraphBuilder()
                 .addDependency(scope, depCyc2)
@@ -225,7 +225,7 @@ class DependencyGraphBuilderTest : WordSpec({
         "check for illegal references when building the graph" {
             val depLang = createDependency("org.apache.commons", "commons-lang3", "3.11")
             val depNoPkg = createDependency(NO_PACKAGE_NAMESPACE, "invalid", "1.2")
-            val depLog = createDependency("commons-logging", "commons-logging", "1.2", dependencies = listOf(depNoPkg))
+            val depLog = createDependency("commons-logging", "commons-logging", "1.2", dependencies = setOf(depNoPkg))
 
             val exception = shouldThrow<IllegalArgumentException> {
                 createGraphBuilder()
@@ -243,7 +243,7 @@ class DependencyGraphBuilderTest : WordSpec({
                 issues = listOf(Issue(source = "test", message = "test issue"))
             )
             val depLog =
-                createDependency("commons-logging", "commons-logging", "1.2", dependencies = listOf(depIssuesPkg))
+                createDependency("commons-logging", "commons-logging", "1.2", dependencies = setOf(depIssuesPkg))
 
             createGraphBuilder()
                 .addDependency("s", depLang)
@@ -263,7 +263,7 @@ class DependencyGraphBuilderTest : WordSpec({
                 "commons-logging",
                 "commons-logging",
                 "1.2",
-                dependencies = listOf(depProjectDynamicPkg, depProjectStaticPkg)
+                dependencies = setOf(depProjectDynamicPkg, depProjectStaticPkg)
             )
 
             createGraphBuilder()
@@ -275,7 +275,7 @@ class DependencyGraphBuilderTest : WordSpec({
         "allow disabling the check for illegal references" {
             val depLang = createDependency("org.apache.commons", "commons-lang3", "3.11")
             val depNoPkg = createDependency(NO_PACKAGE_NAMESPACE, "invalid", "1.2")
-            val depLog = createDependency("commons-logging", "commons-logging", "1.2", dependencies = listOf(depNoPkg))
+            val depLog = createDependency("commons-logging", "commons-logging", "1.2", dependencies = setOf(depNoPkg))
 
             createGraphBuilder()
                 .addDependency("s", depLang)
@@ -383,11 +383,12 @@ private fun createDependency(
     group: String,
     artifact: String,
     version: String,
-    dependencies: List<PackageReference> = emptyList()
-): PackageReference {
-    val id = Identifier("test", group, artifact, version)
-    return PackageReference(id, dependencies = dependencies.toSortedSet())
-}
+    dependencies: Set<PackageReference> = emptySet()
+) =
+    PackageReference(
+        id = Identifier("test", group, artifact, version),
+        dependencies = dependencies
+    )
 
 /**
  * Return the package references from the given [scopes] associated with the scope with the given [scopeName].
diff --git a/model/src/test/kotlin/utils/DependencyGraphConverterTest.kt b/model/src/test/kotlin/utils/DependencyGraphConverterTest.kt
index 3a24a9477f0dd..42857df5dc8a3 100644
--- a/model/src/test/kotlin/utils/DependencyGraphConverterTest.kt
+++ b/model/src/test/kotlin/utils/DependencyGraphConverterTest.kt
@@ -34,7 +34,6 @@ import io.kotest.matchers.shouldNot
 import io.kotest.matchers.types.beTheSameInstanceAs
 
 import java.io.File
-import java.util.SortedSet
 
 import org.ossreviewtoolkit.model.AnalyzerResult
 import org.ossreviewtoolkit.model.DependencyGraphNode
@@ -221,8 +220,8 @@ private fun createIdentifier(managerName: String, index: Int, forProject: Boolea
  * Create a set of [PackageReference]s with the size of [count] simulating the dependencies of a project. Use
  * [managerName], [startIndex] to generate identifiers.
  */
-private fun createDependencies(managerName: String, startIndex: Int, count: Int): SortedSet<PackageReference> =
-    (startIndex..(startIndex + count)).mapTo(sortedSetOf()) { index ->
+private fun createDependencies(managerName: String, startIndex: Int, count: Int): Set<PackageReference> =
+    (startIndex..(startIndex + count)).mapTo(mutableSetOf()) { index ->
         PackageReference(createIdentifier(managerName, index, forProject = false), issues = createIssues(index))
     }
 
diff --git a/plugins/package-managers/bower/src/main/kotlin/Bower.kt b/plugins/package-managers/bower/src/main/kotlin/Bower.kt
index 499e0a19dd8f4..85349f59a1bd6 100644
--- a/plugins/package-managers/bower/src/main/kotlin/Bower.kt
+++ b/plugins/package-managers/bower/src/main/kotlin/Bower.kt
@@ -24,7 +24,6 @@ package org.ossreviewtoolkit.plugins.packagemanagers.bower
 import com.fasterxml.jackson.databind.JsonNode
 
 import java.io.File
-import java.util.SortedSet
 import java.util.Stack
 
 import org.ossreviewtoolkit.analyzer.AbstractPackageManagerFactory
@@ -241,7 +240,7 @@ private fun parseDependencyTree(
     node: JsonNode,
     scopeName: String,
     alternativeNodes: Map<String, JsonNode> = getNodesWithCompleteDependencies(node)
-): SortedSet<PackageReference> {
+): Set<PackageReference> {
     val result = mutableSetOf<PackageReference>()
 
     if (!hasCompleteDependencies(node, scopeName)) {
@@ -265,5 +264,5 @@ private fun parseDependencyTree(
         result += packageReference
     }
 
-    return result.toSortedSet()
+    return result
 }
diff --git a/plugins/package-managers/bundler/src/main/kotlin/Bundler.kt b/plugins/package-managers/bundler/src/main/kotlin/Bundler.kt
index 8a68dddc08b2c..7e954b7dd4352 100644
--- a/plugins/package-managers/bundler/src/main/kotlin/Bundler.kt
+++ b/plugins/package-managers/bundler/src/main/kotlin/Bundler.kt
@@ -250,7 +250,7 @@ class Bundler(
             parseDependency(workingDir, projectId, it, gemSpecs, scopeDependencies, issues)
         }
 
-        scopes += Scope(groupName, scopeDependencies.toSortedSet())
+        scopes += Scope(groupName, scopeDependencies)
     }
 
     private fun parseDependency(
@@ -281,7 +281,7 @@ class Bundler(
                     parseDependency(workingDir, projectId, it, gemSpecs, transitiveDependencies, issues)
                 }
 
-                scopeDependencies += PackageReference(gemId, dependencies = transitiveDependencies.toSortedSet())
+                scopeDependencies += PackageReference(gemId, dependencies = transitiveDependencies)
             }
         }.onFailure {
             it.showStackTrace()
diff --git a/plugins/package-managers/cargo/src/main/kotlin/Cargo.kt b/plugins/package-managers/cargo/src/main/kotlin/Cargo.kt
index 5e7d33eff14f3..59d478069db44 100644
--- a/plugins/package-managers/cargo/src/main/kotlin/Cargo.kt
+++ b/plugins/package-managers/cargo/src/main/kotlin/Cargo.kt
@@ -150,7 +150,7 @@ class Cargo(
             // Filter dev and build dependencies, because they are not transitive.
             val kind = it["kind"].textValueOrEmpty()
             kind != "dev" && kind != "build"
-        }.mapNotNull {
+        }.mapNotNullTo(mutableSetOf()) {
             // TODO: Handle renamed dependencies here, see:
             //       https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html#renaming-dependencies-in-cargotoml
             val dependencyName = it["name"].textValue()
@@ -158,7 +158,7 @@ class Cargo(
             getResolvedVersion(name, version, dependencyName, metadata)?.let { dependencyVersion ->
                 buildDependencyTree(dependencyName, dependencyVersion, packages, metadata)
             }
-        }.toSortedSet()
+        }
 
         val id = parseCargoId(node)
         val pkg = packages.getValue(id)
@@ -200,10 +200,9 @@ class Cargo(
                     val version = getResolvedVersion(projectName, projectVersion, dependencyName, metadata)
                     version?.let { Pair(dependencyName, it) }
                 }
-                .map {
+                .mapTo(mutableSetOf()) {
                     buildDependencyTree(name = it.first, version = it.second, packages = packages, metadata = metadata)
                 }
-                .toSortedSet()
 
             return Scope(scope, transitiveDependencies)
         }
diff --git a/plugins/package-managers/cocoapods/src/main/kotlin/CocoaPods.kt b/plugins/package-managers/cocoapods/src/main/kotlin/CocoaPods.kt
index 8fd6a3eea4e29..224494acd39e8 100644
--- a/plugins/package-managers/cocoapods/src/main/kotlin/CocoaPods.kt
+++ b/plugins/package-managers/cocoapods/src/main/kotlin/CocoaPods.kt
@@ -29,7 +29,6 @@ import com.fasterxml.jackson.databind.node.ObjectNode
 
 import java.io.File
 import java.io.IOException
-import java.util.SortedSet
 
 import org.apache.logging.log4j.kotlin.Logging
 
@@ -232,7 +231,7 @@ private const val SCOPE_NAME = "dependencies"
 
 private val NAME_AND_VERSION_REGEX = "(\\S+)\\s+(.*)".toRegex()
 
-private fun getPackageReferences(podfileLock: File): SortedSet<PackageReference> {
+private fun getPackageReferences(podfileLock: File): Set<PackageReference> {
     val versionForName = mutableMapOf<String, String>()
     val dependenciesForName = mutableMapOf<String, MutableSet<String>>()
     val root = yamlMapper.readTree(podfileLock)
@@ -255,10 +254,10 @@ private fun getPackageReferences(podfileLock: File): SortedSet<PackageReference>
     fun createPackageReference(name: String): PackageReference =
         PackageReference(
             id = Identifier("Pod", "", name, versionForName.getValue(name)),
-            dependencies = dependenciesForName.getValue(name).mapTo(sortedSetOf()) { createPackageReference(it) }
+            dependencies = dependenciesForName.getValue(name).mapTo(mutableSetOf()) { createPackageReference(it) }
         )
 
-    return root.get("DEPENDENCIES").mapTo(sortedSetOf()) { node ->
+    return root.get("DEPENDENCIES").mapTo(mutableSetOf()) { node ->
         val name = node.textValue().substringBefore(" ")
         createPackageReference(name)
     }
diff --git a/plugins/package-managers/composer/src/main/kotlin/Composer.kt b/plugins/package-managers/composer/src/main/kotlin/Composer.kt
index dd3db354b8350..35bfb6efcfb7d 100644
--- a/plugins/package-managers/composer/src/main/kotlin/Composer.kt
+++ b/plugins/package-managers/composer/src/main/kotlin/Composer.kt
@@ -24,7 +24,6 @@ import com.fasterxml.jackson.databind.node.ObjectNode
 
 import java.io.File
 import java.io.IOException
-import java.util.SortedSet
 
 import org.apache.logging.log4j.kotlin.Logging
 
@@ -171,7 +170,7 @@ class Composer(
         packages: Map<String, Package>,
         virtualPackages: Set<String>,
         dependencyBranch: List<String> = emptyList()
-    ): SortedSet<PackageReference> {
+    ): Set<PackageReference> {
         val packageReferences = mutableSetOf<PackageReference>()
 
         dependencies.filterNot { packageName ->
@@ -209,7 +208,7 @@ class Composer(
             }
         }
 
-        return packageReferences.toSortedSet()
+        return packageReferences
     }
 
     private fun parseProject(definitionFile: File, scopes: Set<Scope>): Project {
diff --git a/plugins/package-managers/conan/src/main/kotlin/Conan.kt b/plugins/package-managers/conan/src/main/kotlin/Conan.kt
index 3bfa5e541356c..c20195257ffc5 100644
--- a/plugins/package-managers/conan/src/main/kotlin/Conan.kt
+++ b/plugins/package-managers/conan/src/main/kotlin/Conan.kt
@@ -23,7 +23,6 @@ import com.fasterxml.jackson.databind.JsonNode
 import com.fasterxml.jackson.module.kotlin.readValue
 
 import java.io.File
-import java.util.SortedSet
 
 import org.apache.logging.log4j.kotlin.Logging
 
@@ -268,25 +267,22 @@ class Conan(
         pkg: JsonNode,
         scopeName: String,
         workingDir: File
-    ): SortedSet<PackageReference> {
-        val result = mutableSetOf<PackageReference>()
-
-        pkg[scopeName]?.forEach { childNode ->
-            val childRef = childNode.textValueOrEmpty()
-            pkgInfos.find { it["reference"].textValueOrEmpty() == childRef }?.let { pkgInfo ->
-                logger.debug { "Found child '$childRef'." }
-
-                val id = parsePackageId(pkgInfo, workingDir)
-                val dependencies = parseDependencyTree(pkgInfos, pkgInfo, SCOPE_NAME_DEPENDENCIES, workingDir) +
-                        parseDependencyTree(pkgInfos, pkgInfo, SCOPE_NAME_DEV_DEPENDENCIES, workingDir)
-
-                result += PackageReference(id, dependencies = dependencies.toSortedSet())
+    ): Set<PackageReference> =
+        buildSet {
+            pkg[scopeName]?.forEach { childNode ->
+                val childRef = childNode.textValueOrEmpty()
+                pkgInfos.find { it["reference"].textValueOrEmpty() == childRef }?.let { pkgInfo ->
+                    logger.debug { "Found child '$childRef'." }
+
+                    val id = parsePackageId(pkgInfo, workingDir)
+                    val dependencies = parseDependencyTree(pkgInfos, pkgInfo, SCOPE_NAME_DEPENDENCIES, workingDir) +
+                            parseDependencyTree(pkgInfos, pkgInfo, SCOPE_NAME_DEV_DEPENDENCIES, workingDir)
+
+                    this += PackageReference(id, dependencies = dependencies)
+                }
             }
         }
 
-        return result.toSortedSet()
-    }
-
     /**
      * Run through each package and parse the list of its dependencies (also transitive ones).
      */
@@ -295,7 +291,7 @@ class Conan(
         definitionFileName: String,
         scopeName: String,
         workingDir: File
-    ): SortedSet<PackageReference> =
+    ): Set<PackageReference> =
         parseDependencyTree(pkgInfos, findProjectNode(pkgInfos, definitionFileName), scopeName, workingDir)
 
     /**
diff --git a/plugins/package-managers/gradle-inspector/src/main/kotlin/GradleInspector.kt b/plugins/package-managers/gradle-inspector/src/main/kotlin/GradleInspector.kt
index 6557c4ab16238..506d131264309 100644
--- a/plugins/package-managers/gradle-inspector/src/main/kotlin/GradleInspector.kt
+++ b/plugins/package-managers/gradle-inspector/src/main/kotlin/GradleInspector.kt
@@ -24,7 +24,6 @@ import OrtDependencyTreeModel
 
 import java.io.ByteArrayOutputStream
 import java.io.File
-import java.util.SortedSet
 import java.util.concurrent.TimeUnit
 
 import org.apache.logging.log4j.kotlin.Logging
@@ -291,8 +290,8 @@ class GradleInspector(
  */
 private fun Collection<OrtDependency>.toPackageRefs(
     packageDependencies: MutableCollection<OrtDependency>
-): SortedSet<PackageReference> =
-    mapTo(sortedSetOf()) { dep ->
+): Set<PackageReference> =
+    mapTo(mutableSetOf()) { dep ->
         val (id, linkage) = if (dep.localPath != null) {
             val id = Identifier("Gradle", dep.groupId, dep.artifactId, dep.version)
             id to PackageLinkage.PROJECT_DYNAMIC
diff --git a/plugins/package-managers/nuget/src/main/kotlin/utils/NuGetInspector.kt b/plugins/package-managers/nuget/src/main/kotlin/utils/NuGetInspector.kt
index 7b4d99b114f6f..d26bca3204203 100644
--- a/plugins/package-managers/nuget/src/main/kotlin/utils/NuGetInspector.kt
+++ b/plugins/package-managers/nuget/src/main/kotlin/utils/NuGetInspector.kt
@@ -184,8 +184,8 @@ internal fun NuGetInspector.Result.toOrtProject(
     )
 }
 
-private fun List<NuGetInspector.PackageData>.toPackageReferences(): SortedSet<PackageReference> =
-    mapTo(sortedSetOf()) { data ->
+private fun List<NuGetInspector.PackageData>.toPackageReferences(): Set<PackageReference> =
+    mapTo(mutableSetOf()) { data ->
         PackageReference(
             id = Identifier(type = TYPE, namespace = "", name = data.name, version = data.version.orEmpty()),
             dependencies = data.dependencies.toPackageReferences(),
diff --git a/plugins/package-managers/pub/src/main/kotlin/Pub.kt b/plugins/package-managers/pub/src/main/kotlin/Pub.kt
index 78df635ebf3b2..1e0ad1b4b2f86 100644
--- a/plugins/package-managers/pub/src/main/kotlin/Pub.kt
+++ b/plugins/package-managers/pub/src/main/kotlin/Pub.kt
@@ -24,7 +24,6 @@ import com.fasterxml.jackson.dataformat.yaml.JacksonYAMLParseException
 
 import java.io.File
 import java.io.IOException
-import java.util.SortedSet
 
 import org.apache.logging.log4j.kotlin.Logging
 
@@ -267,14 +266,14 @@ class Pub(
                         .toList()
 
                     if (gradleDefinitionFiles.isNotEmpty()) {
-                        val gradleDependencies = gradleDefinitionFiles.map {
+                        val gradleDependencies = gradleDefinitionFiles.mapTo(mutableSetOf()) {
                             PackageManagerDependencyHandler.createPackageManagerDependency(
                                 packageManager = gradleFactory.type,
                                 definitionFile = VersionControlSystem.getPathInfo(it).path,
                                 scope = "releaseCompileClasspath",
                                 linkage = PackageLinkage.PROJECT_STATIC
                             )
-                        }.toSortedSet()
+                        }
 
                         scopes += Scope("android", gradleDependencies)
                     }
@@ -331,7 +330,7 @@ class Pub(
         labels: Map<String, String>,
         workingDir: File,
         processedPackages: Set<String> = emptySet()
-    ): SortedSet<PackageReference> {
+    ): Set<PackageReference> {
         val packageReferences = mutableSetOf<PackageReference>()
         val nameOfCurrentPackage = manifest["name"].textValue()
         val containsFlutter = "flutter" in dependencies
@@ -403,7 +402,7 @@ class Pub(
             }
         }
 
-        return packageReferences.toSortedSet()
+        return packageReferences
     }
 
     private val analyzerResultCacheAndroid = mutableMapOf<String, List<ProjectAnalyzerResult>>()
diff --git a/plugins/package-managers/python/src/main/kotlin/utils/PythonInspector.kt b/plugins/package-managers/python/src/main/kotlin/utils/PythonInspector.kt
index ed1258a19b5e4..79691ee426d5a 100644
--- a/plugins/package-managers/python/src/main/kotlin/utils/PythonInspector.kt
+++ b/plugins/package-managers/python/src/main/kotlin/utils/PythonInspector.kt
@@ -20,7 +20,6 @@
 package org.ossreviewtoolkit.plugins.packagemanagers.python.utils
 
 import java.io.File
-import java.util.SortedSet
 
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
@@ -344,8 +343,8 @@ private fun List<PythonInspector.Party>.toAuthors(): Set<String> =
         }.takeIf { it.isNotBlank() }
     }
 
-private fun List<PythonInspector.ResolvedDependency>.toPackageReferences(): SortedSet<PackageReference> =
-    mapTo(sortedSetOf()) { it.toPackageReference() }
+private fun List<PythonInspector.ResolvedDependency>.toPackageReferences(): Set<PackageReference> =
+    mapTo(mutableSetOf()) { it.toPackageReference() }
 
 private fun PythonInspector.ResolvedDependency.toPackageReference() =
     PackageReference(
diff --git a/plugins/package-managers/spdx/src/main/kotlin/SpdxDocumentFile.kt b/plugins/package-managers/spdx/src/main/kotlin/SpdxDocumentFile.kt
index d352761671ddb..be7b251ea29ff 100644
--- a/plugins/package-managers/spdx/src/main/kotlin/SpdxDocumentFile.kt
+++ b/plugins/package-managers/spdx/src/main/kotlin/SpdxDocumentFile.kt
@@ -22,7 +22,6 @@
 package org.ossreviewtoolkit.plugins.packagemanagers.spdx
 
 import java.io.File
-import java.util.SortedSet
 
 import org.apache.logging.log4j.kotlin.Logging
 
@@ -335,7 +334,7 @@ class SpdxDocumentFile(
         pkgId: String,
         doc: SpdxResolvedDocument,
         packages: MutableSet<Package>
-    ): SortedSet<PackageReference> =
+    ): Set<PackageReference> =
         getDependencies(pkgId, doc, packages, SpdxRelationship.Type.DEPENDENCY_OF) { target ->
             val issues = mutableListOf<Issue>()
             getPackageManagerDependency(target, doc) ?: doc.getSpdxPackageForId(target, issues)?.let { dependency ->
@@ -390,8 +389,8 @@ class SpdxDocumentFile(
         packages: MutableSet<Package>,
         dependencyOfRelation: SpdxRelationship.Type,
         dependsOnCase: (String) -> PackageReference? = { null }
-    ): SortedSet<PackageReference> =
-        doc.relationships.mapNotNullTo(sortedSetOf()) { (source, relation, target, _) ->
+    ): Set<PackageReference> =
+        doc.relationships.mapNotNullTo(mutableSetOf()) { (source, relation, target, _) ->
             val issues = mutableListOf<Issue>()
 
             val isDependsOnRelation = relation == SpdxRelationship.Type.DEPENDS_ON || hasDefaultScopeLinkage(
diff --git a/plugins/package-managers/stack/src/main/kotlin/Stack.kt b/plugins/package-managers/stack/src/main/kotlin/Stack.kt
index 8677bb94c641f..0b611cd35f35e 100644
--- a/plugins/package-managers/stack/src/main/kotlin/Stack.kt
+++ b/plugins/package-managers/stack/src/main/kotlin/Stack.kt
@@ -24,7 +24,6 @@ import com.fasterxml.jackson.module.kotlin.readValue
 
 import java.io.File
 import java.io.IOException
-import java.util.SortedSet
 
 import org.apache.logging.log4j.kotlin.Logging
 
@@ -190,8 +189,8 @@ class Stack(
             if (pkg != null && pkg.id.name != "ghc") dependencyPackageMap[dependency] = pkg
         }
 
-        fun List<String>.toPackageReferences(): SortedSet<PackageReference> =
-            mapNotNullTo(sortedSetOf()) { name ->
+        fun List<String>.toPackageReferences(): Set<PackageReference> =
+            mapNotNullTo(mutableSetOf()) { name ->
                 // TODO: Stack identifies dependencies only by name. Find out how dependencies with the same name but in
                 //       different namespaces should be handled.
                 dependencyPackageMap.entries.find { (dependency, _) -> dependency.name == name }?.let { entry ->
diff --git a/plugins/reporters/evaluated-model/src/main/kotlin/EvaluatedModelMapper.kt b/plugins/reporters/evaluated-model/src/main/kotlin/EvaluatedModelMapper.kt
index 2cfe624fde4f7..002c2f22ed836 100644
--- a/plugins/reporters/evaluated-model/src/main/kotlin/EvaluatedModelMapper.kt
+++ b/plugins/reporters/evaluated-model/src/main/kotlin/EvaluatedModelMapper.kt
@@ -492,7 +492,7 @@ internal class EvaluatedModelMapper(private val input: ReporterInput) {
             visitedNodes += getInternalId() to createDependencyNode(dependency, linkage, issues)
 
             val children = visitDependencies { dependencies ->
-                dependencies.map { node ->
+                dependencies.sortedBy { it.id }.map { node ->
                     val nodeId = node.getInternalId()
 
                     if (deduplicateDependencyTree && nodeId in visitedNodes) {
@@ -511,9 +511,8 @@ internal class EvaluatedModelMapper(private val input: ReporterInput) {
             // Deduplication should not happen across scopes.
             visitedNodes.clear()
 
-            val subTrees = input.ortResult.dependencyNavigator.directDependencies(project, scope).map {
-                it.toEvaluatedTreeNode(scopes.getValue(scope), mutableListOf())
-            }.toList()
+            val subTrees = input.ortResult.dependencyNavigator.directDependencies(project, scope).sortedBy { it.id }
+                .mapTo(mutableListOf()) { it.toEvaluatedTreeNode(scopes.getValue(scope), mutableListOf()) }
 
             val applicableScopeExcludes = input.ortResult.getExcludes().findScopeExcludes(scope)
             val evaluatedScopeExcludes = scopeExcludes.addIfRequired(applicableScopeExcludes)
diff --git a/plugins/reporters/gitlab/src/funTest/kotlin/GitLabLicenseModelReporterFunTest.kt b/plugins/reporters/gitlab/src/funTest/kotlin/GitLabLicenseModelReporterFunTest.kt
index ec0306eab909c..5255d3bbd8660 100644
--- a/plugins/reporters/gitlab/src/funTest/kotlin/GitLabLicenseModelReporterFunTest.kt
+++ b/plugins/reporters/gitlab/src/funTest/kotlin/GitLabLicenseModelReporterFunTest.kt
@@ -95,7 +95,7 @@ private fun createOrtResult(): OrtResult {
                         scopeDependencies = setOf(
                             Scope(
                                 name = "compile",
-                                dependencies = sortedSetOf(
+                                dependencies = setOf(
                                     PackageReference(
                                         id = Identifier("Maven:some-group:first-package:0.0.1")
                                     )
@@ -103,7 +103,7 @@ private fun createOrtResult(): OrtResult {
                             ),
                             Scope(
                                 name = "test",
-                                dependencies = sortedSetOf(
+                                dependencies = setOf(
                                     PackageReference(
                                         id = Identifier("Maven:some-group:excluded-package:0.0.4")
                                     )
@@ -116,7 +116,7 @@ private fun createOrtResult(): OrtResult {
                         scopeDependencies = setOf(
                             Scope(
                                 name = "install",
-                                dependencies = sortedSetOf(
+                                dependencies = setOf(
                                     PackageReference(
                                         id = Identifier("PIP::second-package:0.0.2")
                                     )
diff --git a/plugins/reporters/opossum/src/test/kotlin/OpossumReporterTest.kt b/plugins/reporters/opossum/src/test/kotlin/OpossumReporterTest.kt
index c7ae99ff555f7..1d91a62a3b155 100644
--- a/plugins/reporters/opossum/src/test/kotlin/OpossumReporterTest.kt
+++ b/plugins/reporters/opossum/src/test/kotlin/OpossumReporterTest.kt
@@ -266,7 +266,7 @@ private fun createOrtResult(): OrtResult {
                         scopeDependencies = setOf(
                             Scope(
                                 name = "compile",
-                                dependencies = sortedSetOf(
+                                dependencies = setOf(
                                     PackageReference(
                                         id = Identifier("Maven:first-package-group:first-package:0.0.1")
                                     ),
@@ -286,7 +286,7 @@ private fun createOrtResult(): OrtResult {
                             ),
                             Scope(
                                 name = "test",
-                                dependencies = sortedSetOf(
+                                dependencies = setOf(
                                     PackageReference(
                                         id = Identifier("Maven:fifth-package-group:fifth-package:0.0.1")
                                     )
@@ -303,16 +303,16 @@ private fun createOrtResult(): OrtResult {
                         scopeDependencies = setOf(
                             Scope(
                                 name = "devDependencies",
-                                dependencies = sortedSetOf(
+                                dependencies = setOf(
                                     PackageReference(
                                         id = Identifier("NPM:@something:somepackage:1.2.3"),
-                                        dependencies = sortedSetOf(
+                                        dependencies = setOf(
                                             PackageReference(
                                                 id = Identifier("NPM:@something:somepackage-dep:1.2.3"),
-                                                dependencies = sortedSetOf(
+                                                dependencies = setOf(
                                                     PackageReference(
                                                         id = Identifier("NPM:@something:somepackage-dep-dep:1.2.3"),
-                                                        dependencies = sortedSetOf(
+                                                        dependencies = setOf(
                                                             PackageReference(
                                                                 id = Identifier(
                                                                     "NPM:@something:" +
diff --git a/plugins/reporters/spdx/src/funTest/assets/spdx-document-reporter-expected-output.spdx.json b/plugins/reporters/spdx/src/funTest/assets/spdx-document-reporter-expected-output.spdx.json
index 0298f85940e43..2397a6bfad36f 100644
--- a/plugins/reporters/spdx/src/funTest/assets/spdx-document-reporter-expected-output.spdx.json
+++ b/plugins/reporters/spdx/src/funTest/assets/spdx-document-reporter-expected-output.spdx.json
@@ -155,11 +155,15 @@
   "relationships" : [ {
     "spdxElementId" : "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1",
     "relationshipType" : "GENERATED_FROM",
-    "relatedSpdxElement" : "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1-vcs"
+    "relatedSpdxElement" : "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1-source-artifact"
   }, {
     "spdxElementId" : "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1",
     "relationshipType" : "GENERATED_FROM",
-    "relatedSpdxElement" : "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1-source-artifact"
+    "relatedSpdxElement" : "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1-vcs"
+  }, {
+    "spdxElementId" : "SPDXRef-Project-Maven-first-project-group-first-project-name-0.0.1",
+    "relationshipType" : "DEPENDS_ON",
+    "relatedSpdxElement" : "SPDXRef-Package-Maven-fifth-package-group-fifth-package-0.0.1"
   }, {
     "spdxElementId" : "SPDXRef-Project-Maven-first-project-group-first-project-name-0.0.1",
     "relationshipType" : "DEPENDS_ON",
@@ -180,9 +184,5 @@
     "spdxElementId" : "SPDXRef-Project-Maven-first-project-group-first-project-name-0.0.1",
     "relationshipType" : "DEPENDS_ON",
     "relatedSpdxElement" : "SPDXRef-Package-Maven-third-package-group-third-package-0.0.1"
-  }, {
-    "spdxElementId" : "SPDXRef-Project-Maven-first-project-group-first-project-name-0.0.1",
-    "relationshipType" : "DEPENDS_ON",
-    "relatedSpdxElement" : "SPDXRef-Package-Maven-fifth-package-group-fifth-package-0.0.1"
   } ]
 }
\ No newline at end of file
diff --git a/plugins/reporters/spdx/src/funTest/assets/spdx-document-reporter-expected-output.spdx.yml b/plugins/reporters/spdx/src/funTest/assets/spdx-document-reporter-expected-output.spdx.yml
index 0609f4e009eaf..fe28cc62cd7f6 100644
--- a/plugins/reporters/spdx/src/funTest/assets/spdx-document-reporter-expected-output.spdx.yml
+++ b/plugins/reporters/spdx/src/funTest/assets/spdx-document-reporter-expected-output.spdx.yml
@@ -166,10 +166,13 @@ packages:
 relationships:
 - spdxElementId: "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1"
   relationshipType: "GENERATED_FROM"
-  relatedSpdxElement: "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1-vcs"
+  relatedSpdxElement: "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1-source-artifact"
 - spdxElementId: "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1"
   relationshipType: "GENERATED_FROM"
-  relatedSpdxElement: "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1-source-artifact"
+  relatedSpdxElement: "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1-vcs"
+- spdxElementId: "SPDXRef-Project-Maven-first-project-group-first-project-name-0.0.1"
+  relationshipType: "DEPENDS_ON"
+  relatedSpdxElement: "SPDXRef-Package-Maven-fifth-package-group-fifth-package-0.0.1"
 - spdxElementId: "SPDXRef-Project-Maven-first-project-group-first-project-name-0.0.1"
   relationshipType: "DEPENDS_ON"
   relatedSpdxElement: "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1"
@@ -185,6 +188,3 @@ relationships:
 - spdxElementId: "SPDXRef-Project-Maven-first-project-group-first-project-name-0.0.1"
   relationshipType: "DEPENDS_ON"
   relatedSpdxElement: "SPDXRef-Package-Maven-third-package-group-third-package-0.0.1"
-- spdxElementId: "SPDXRef-Project-Maven-first-project-group-first-project-name-0.0.1"
-  relationshipType: "DEPENDS_ON"
-  relatedSpdxElement: "SPDXRef-Package-Maven-fifth-package-group-fifth-package-0.0.1"
diff --git a/plugins/reporters/spdx/src/funTest/kotlin/SpdxDocumentReporterFunTest.kt b/plugins/reporters/spdx/src/funTest/kotlin/SpdxDocumentReporterFunTest.kt
index 2dedd03bd9551..cf8e8ed2fcdb1 100644
--- a/plugins/reporters/spdx/src/funTest/kotlin/SpdxDocumentReporterFunTest.kt
+++ b/plugins/reporters/spdx/src/funTest/kotlin/SpdxDocumentReporterFunTest.kt
@@ -165,7 +165,7 @@ private val ortResult = OrtResult(
                     scopeDependencies = setOf(
                         Scope(
                             name = "compile",
-                            dependencies = sortedSetOf(
+                            dependencies = setOf(
                                 PackageReference(
                                     id = Identifier("Maven:first-package-group:first-package:0.0.1")
                                 ),
@@ -185,7 +185,7 @@ private val ortResult = OrtResult(
                         ),
                         Scope(
                             name = "test",
-                            dependencies = sortedSetOf(
+                            dependencies = setOf(
                                 PackageReference(
                                     id = Identifier("Maven:fifth-package-group:fifth-package:0.0.1")
                                 )
diff --git a/reporter/src/testFixtures/kotlin/TestData.kt b/reporter/src/testFixtures/kotlin/TestData.kt
index cac44cf2c15f9..a9fc47a4c9c14 100644
--- a/reporter/src/testFixtures/kotlin/TestData.kt
+++ b/reporter/src/testFixtures/kotlin/TestData.kt
@@ -96,7 +96,7 @@ val ORT_RESULT = OrtResult(
                     scopeDependencies = setOf(
                         Scope(
                             name = "dependencies",
-                            dependencies = sortedSetOf(
+                            dependencies = setOf(
                                 PackageReference(
                                     id = Identifier("NPM:@ort:no-license-file:1.0")
                                 ),
@@ -116,7 +116,7 @@ val ORT_RESULT = OrtResult(
                         ),
                         Scope(
                             name = "devDependencies",
-                            dependencies = sortedSetOf(
+                            dependencies = setOf(
                                 PackageReference(
                                     id = Identifier("NPM:@ort:declared-license:1.0")
                                 ),
@@ -133,7 +133,7 @@ val ORT_RESULT = OrtResult(
                     scopeDependencies = setOf(
                         Scope(
                             name = "dependencies",
-                            dependencies = sortedSetOf()
+                            dependencies = emptySet()
                         )
                     )
                 ),
diff --git a/utils/spdx/build.gradle.kts b/utils/spdx/build.gradle.kts
index 3f6f6c25ec13a..f30635089a5fa 100644
--- a/utils/spdx/build.gradle.kts
+++ b/utils/spdx/build.gradle.kts
@@ -81,6 +81,8 @@ dependencies {
     implementation(libs.jacksonDataformatYaml)
     implementation(libs.jacksonDatatypeJsr310)
     implementation(libs.jacksonModuleKotlin)
+
+    testImplementation(libs.kotestAssertionsJson)
 }
 
 data class LicenseInfo(
diff --git a/utils/spdx/src/main/kotlin/model/Converters.kt b/utils/spdx/src/main/kotlin/model/Converters.kt
new file mode 100644
index 0000000000000..9de05c14449ff
--- /dev/null
+++ b/utils/spdx/src/main/kotlin/model/Converters.kt
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2023 The ORT Project Authors (see <https://github.com/oss-review-toolkit/ort/blob/main/NOTICE>)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * License-Filename: LICENSE
+ */
+
+@file:Suppress("Filename", "MatchingDeclarationName")
+
+package org.ossreviewtoolkit.utils.spdx.model
+
+import com.fasterxml.jackson.databind.util.StdConverter
+
+import java.util.SortedSet
+
+internal class SpdxRelationshipSortedSetConverter :
+    StdConverter<List<SpdxRelationship>, SortedSet<SpdxRelationship>>() {
+    override fun convert(value: List<SpdxRelationship>) =
+        value.toSortedSet(
+            compareBy<SpdxRelationship> { it.spdxElementId }
+                .thenBy { it.relatedSpdxElement }
+                .thenBy { it.relationshipType }
+        )
+}
+
+// TODO: Add more converters for SpdxDocument to improve serialization, see
+//       https://github.com/oss-review-toolkit/ort/issues/7023.
diff --git a/utils/spdx/src/main/kotlin/model/SpdxDocument.kt b/utils/spdx/src/main/kotlin/model/SpdxDocument.kt
index d44d55318f09b..117e1391b9a87 100644
--- a/utils/spdx/src/main/kotlin/model/SpdxDocument.kt
+++ b/utils/spdx/src/main/kotlin/model/SpdxDocument.kt
@@ -21,6 +21,7 @@ package org.ossreviewtoolkit.utils.spdx.model
 
 import com.fasterxml.jackson.annotation.JsonInclude
 import com.fasterxml.jackson.annotation.JsonProperty
+import com.fasterxml.jackson.databind.annotation.JsonSerialize
 
 import org.ossreviewtoolkit.utils.common.getDuplicates
 import org.ossreviewtoolkit.utils.spdx.SpdxConstants.REF_PREFIX
@@ -127,6 +128,7 @@ data class SpdxDocument(
      * All relationships described in this [SpdxDocument].
      */
     @JsonInclude(JsonInclude.Include.NON_EMPTY)
+    @JsonSerialize(converter = SpdxRelationshipSortedSetConverter::class)
     val relationships: List<SpdxRelationship> = emptyList()
 ) {
     init {
diff --git a/utils/spdx/src/test/kotlin/model/SpdxDocumentTest.kt b/utils/spdx/src/test/kotlin/model/SpdxDocumentTest.kt
index 5b97f9b0f53a9..af271917d193b 100644
--- a/utils/spdx/src/test/kotlin/model/SpdxDocumentTest.kt
+++ b/utils/spdx/src/test/kotlin/model/SpdxDocumentTest.kt
@@ -21,14 +21,16 @@ package org.ossreviewtoolkit.utils.spdx.model
 
 import com.fasterxml.jackson.databind.exc.ValueInstantiationException
 
+import io.kotest.assertions.json.ArrayOrder
+import io.kotest.assertions.json.shouldEqualJson
 import io.kotest.assertions.throwables.shouldThrow
 import io.kotest.core.spec.style.WordSpec
-import io.kotest.matchers.shouldBe
 import io.kotest.matchers.string.shouldContain
 
 import java.io.File
 
 import org.ossreviewtoolkit.utils.spdx.SpdxModelMapper
+import org.ossreviewtoolkit.utils.spdx.yamlMapper
 
 /**
  * This test uses the following test assets copied from the SPDX 2.2.1 specification examples.
@@ -52,13 +54,13 @@ class SpdxDocumentTest : WordSpec({
 
     "The official YAML example without ranges from the SPDX specification version 2.2" should {
         "have idempotent (de)-serialization" {
-            val yaml = spdxExamplesDir.resolve("SPDXYAMLExample-2.2-no-ranges.spdx.yaml")
-            val document = SpdxModelMapper.read<SpdxDocument>(yaml)
+            val yaml = spdxExamplesDir.resolve("SPDXYAMLExample-2.2-no-ranges.spdx.yaml").readText()
 
-            val serializedYaml = SpdxModelMapper.toYaml(document)
-            val deserializedYaml = SpdxModelMapper.fromYaml<SpdxDocument>(serializedYaml)
+            val reSerializedYaml = SpdxModelMapper.fromYaml<SpdxDocument>(yaml).let {
+                SpdxModelMapper.toYaml(it)
+            }
 
-            deserializedYaml shouldBe document
+            reSerializedYaml lenientShouldEqualYaml yaml
         }
     }
 
@@ -72,13 +74,13 @@ class SpdxDocumentTest : WordSpec({
 
     "The official JSON example without ranges from the SPDX specification version 2.2" should {
         "have idempotent (de-)serialization" {
-            val json = spdxExamplesDir.resolve("SPDXJSONExample-v2.2-no-ranges.spdx.json")
-            val document = SpdxModelMapper.read<SpdxDocument>(json)
+            val json = spdxExamplesDir.resolve("SPDXJSONExample-v2.2-no-ranges.spdx.json").readText()
 
-            val serializedJson = SpdxModelMapper.toJson(document)
-            val deserializedJson = SpdxModelMapper.fromJson<SpdxDocument>(serializedJson)
+            val reSerializedJson = SpdxModelMapper.fromJson<SpdxDocument>(json).let {
+                SpdxModelMapper.toJson(it)
+            }
 
-            deserializedJson shouldBe document
+            reSerializedJson lenientShouldEqualJson json
         }
     }
 
@@ -97,3 +99,16 @@ class SpdxDocumentTest : WordSpec({
         }
     }
 })
+
+private infix fun String.lenientShouldEqualJson(expected: String): String =
+    shouldEqualJson {
+        arrayOrder = ArrayOrder.Lenient
+        expected
+    }
+
+private infix fun String.lenientShouldEqualYaml(expected: String): String {
+    val json = yamlMapper.readTree(this).toString()
+    val expectedJson = yamlMapper.readTree(expected).toString()
+
+    return json.lenientShouldEqualJson(expectedJson)
+}
diff --git a/utils/test/src/main/kotlin/OrtResultDsl.kt b/utils/test/src/main/kotlin/OrtResultDsl.kt
index 92f80325761b5..fe31815d1a39d 100644
--- a/utils/test/src/main/kotlin/OrtResultDsl.kt
+++ b/utils/test/src/main/kotlin/OrtResultDsl.kt
@@ -19,8 +19,6 @@
 
 package org.ossreviewtoolkit.utils.test
 
-import java.util.SortedSet
-
 import org.ossreviewtoolkit.model.AnalyzerResult
 import org.ossreviewtoolkit.model.AnalyzerRun
 import org.ossreviewtoolkit.model.Identifier
@@ -55,8 +53,8 @@ class OrtResultBuilder {
             return pkg
         }
 
-        private fun getDependencies(ids: Set<String>): SortedSet<PackageReference> =
-            ids.mapTo(sortedSetOf()) {
+        private fun getDependencies(ids: Set<String>): Set<PackageReference> =
+            ids.mapTo(mutableSetOf()) {
                 PackageReference(
                     id = Identifier(it),
                     dependencies = getDependencies(this@OrtResultBuilder.parentChildIds[it].orEmpty())