diff --git a/.swiftpm/xcode/package.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings b/.swiftpm/xcode/package.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings
new file mode 100644
index 0000000..54782e3
--- /dev/null
+++ b/.swiftpm/xcode/package.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEWorkspaceSharedSettings_AutocreateContextsIfNeeded</key>
+	<true/>
+</dict>
+</plist>
diff --git a/.swiftpm/xcode/xcshareddata/xcschemes/WhoopDIKit.xcscheme b/.swiftpm/xcode/xcshareddata/xcschemes/WhoopDIKit.xcscheme
new file mode 100644
index 0000000..c9d3213
--- /dev/null
+++ b/.swiftpm/xcode/xcshareddata/xcschemes/WhoopDIKit.xcscheme
@@ -0,0 +1,79 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1600"
+   version = "1.7">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES"
+      buildArchitectures = "Automatic">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "WhoopDIKit"
+               BuildableName = "WhoopDIKit"
+               BlueprintName = "WhoopDIKit"
+               ReferencedContainer = "container:">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      shouldAutocreateTestPlan = "YES">
+      <Testables>
+         <TestableReference
+            skipped = "NO">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "WhoopDIKitTests"
+               BuildableName = "WhoopDIKitTests"
+               BlueprintName = "WhoopDIKitTests"
+               ReferencedContainer = "container:">
+            </BuildableReference>
+         </TestableReference>
+      </Testables>
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "WhoopDIKit"
+            BuildableName = "WhoopDIKit"
+            BlueprintName = "WhoopDIKit"
+            ReferencedContainer = "container:">
+         </BuildableReference>
+      </MacroExpansion>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>
diff --git a/Package.resolved b/Package.resolved
index fa0a833..8fd79da 100644
--- a/Package.resolved
+++ b/Package.resolved
@@ -1,14 +1,15 @@
 {
+  "originHash" : "3262a5846ea4516117d0058e3c3efc147f6e7e7eafb82b0dd6de03a2d3e001d4",
   "pins" : [
     {
       "identity" : "swift-syntax",
       "kind" : "remoteSourceControl",
-      "location" : "https://github.com/apple/swift-syntax.git",
+      "location" : "https://github.com/swiftlang/swift-syntax.git",
       "state" : {
-        "revision" : "64889f0c732f210a935a0ad7cda38f77f876262d",
-        "version" : "509.1.1"
+        "revision" : "0687f71944021d616d34d922343dcef086855920",
+        "version" : "600.0.1"
       }
     }
   ],
-  "version" : 2
+  "version" : 3
 }
diff --git a/Package.swift b/Package.swift
index 1863d5a..c5d8e1b 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version:5.9
+// swift-tools-version:6.0
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import CompilerPluginSupport
@@ -14,10 +14,10 @@ let package = Package(
     products: [
         .library(
             name: "WhoopDIKit",
-            targets: ["WhoopDIKit", "WhoopDIKitMacros"]),
+            targets: ["WhoopDIKit",]),
     ],
     dependencies: [
-        .package(url: "https://github.com/apple/swift-syntax.git", from: "509.0.0")
+        .package(url: "https://github.com/swiftlang/swift-syntax.git", from: "600.0.0-latest")
     ],
     targets: [
         .target(
diff --git a/Sources/WhoopDIKit/ServiceKey.swift b/Sources/WhoopDIKit/ServiceKey.swift
index 657c19e..07ed707 100644
--- a/Sources/WhoopDIKit/ServiceKey.swift
+++ b/Sources/WhoopDIKit/ServiceKey.swift
@@ -1,6 +1,6 @@
 /// Hashable wrapper for a metatype value.
 /// See https://stackoverflow.com/questions/42459484/make-a-swift-dictionary-where-the-key-is-type
-public struct ServiceKey {
+public struct ServiceKey: Sendable {
     public let type: Any.Type
     public let name: String?
     
diff --git a/Sources/WhoopDIKit/WhoopDI.swift b/Sources/WhoopDIKit/WhoopDI.swift
index c2026d3..e08279a 100644
--- a/Sources/WhoopDIKit/WhoopDI.swift
+++ b/Sources/WhoopDIKit/WhoopDI.swift
@@ -1,7 +1,7 @@
 import Foundation
 public final class WhoopDI: DependencyRegister {
-    private static let serviceDict = ServiceDictionary<DependencyDefinition>()
-    private static var localServiceDict: ServiceDictionary<DependencyDefinition>? = nil
+    nonisolated(unsafe) private static let serviceDict = ServiceDictionary<DependencyDefinition>()
+    nonisolated(unsafe) private static var localServiceDict: ServiceDictionary<DependencyDefinition>? = nil
     
     /// Registers a list of modules with the DI system.
     /// Typically you will create a `DependencyModule` for your feature, then add it to the module list provided to this method.
diff --git a/Tests/WhoopDIKitTests/InjectableTests.swift b/Tests/WhoopDIKitTests/InjectableTests.swift
index 4670850..a21676f 100644
--- a/Tests/WhoopDIKitTests/InjectableTests.swift
+++ b/Tests/WhoopDIKitTests/InjectableTests.swift
@@ -1,8 +1,12 @@
 import Foundation
-@testable import WhoopDIKitMacros
 import SwiftSyntaxMacrosTestSupport
 import XCTest
 
+// Macro implementations build for the host, so the corresponding module is not available when cross-compiling.
+// Cross-compiled tests may still make use of the macro itself in end-to-end tests.
+#if canImport(WhoopDIKitMacros)
+@testable import WhoopDIKitMacros
+
 final class InjectableTests: XCTestCase {
     func testBasicInject() {
         assertMacroExpansion(
@@ -132,3 +136,4 @@ final class InjectableTests: XCTestCase {
             macros: ["Injectable": InjectableMacro.self])
     }
 }
+#endif