diff --git a/plugins/org.eclipse.elk.core.meta.ui/src/org/eclipse/elk/core/meta/ui/MetaDataUiModule.xtend b/plugins/org.eclipse.elk.core.meta.ui/src/org/eclipse/elk/core/meta/ui/MetaDataUiModule.xtend
index adbf92b137..50782e5a61 100644
--- a/plugins/org.eclipse.elk.core.meta.ui/src/org/eclipse/elk/core/meta/ui/MetaDataUiModule.xtend
+++ b/plugins/org.eclipse.elk.core.meta.ui/src/org/eclipse/elk/core/meta/ui/MetaDataUiModule.xtend
@@ -9,11 +9,24 @@
  *******************************************************************************/
 package org.eclipse.elk.core.meta.ui
 
+import org.eclipse.elk.core.meta.validation.MelkUniqueClassNameValidator
 import org.eclipse.xtend.lib.annotations.FinalFieldsConstructor
+import org.eclipse.xtext.service.SingletonBinding
 
 /**
  * Use this class to register components to be used within the Eclipse IDE.
  */
 @FinalFieldsConstructor
 class MetaDataUiModule extends AbstractMetaDataUiModule {
+    
+// If the Metacompiler has hiccups this can be used to always generate the Java source files, 
+// regardles of any errors.
+//    override bindIShouldGenerate() {
+//        return Always
+//    }
+    
+    @SingletonBinding(eager = true)
+    override bindUniqueClassNameValidator() {
+        return MelkUniqueClassNameValidator
+    }
 }
diff --git a/plugins/org.eclipse.elk.core.meta/src/org/eclipse/elk/core/meta/MetaDataRuntimeModule.xtend b/plugins/org.eclipse.elk.core.meta/src/org/eclipse/elk/core/meta/MetaDataRuntimeModule.xtend
index 52b98a5a10..a61fa406f5 100644
--- a/plugins/org.eclipse.elk.core.meta/src/org/eclipse/elk/core/meta/MetaDataRuntimeModule.xtend
+++ b/plugins/org.eclipse.elk.core.meta/src/org/eclipse/elk/core/meta/MetaDataRuntimeModule.xtend
@@ -15,6 +15,8 @@ import org.eclipse.elk.core.meta.jvmmodel.MelkDocumentationGenerator
 import org.eclipse.xtext.generator.IOutputConfigurationProvider
 import org.eclipse.xtext.generator.OutputConfiguration
 import org.eclipse.xtext.generator.OutputConfigurationProvider
+import org.eclipse.elk.core.meta.validation.MelkUniqueClassNameValidator
+import org.eclipse.xtext.service.SingletonBinding
 
 /**
  * Use this class to register components to be used at runtime / without the Equinox extension registry.
@@ -25,6 +27,11 @@ class MetaDataRuntimeModule extends AbstractMetaDataRuntimeModule {
         return MelkDocumentationGenerator
     }
     
+    @SingletonBinding(eager = true)
+    override bindUniqueClassNameValidator() {
+        return MelkUniqueClassNameValidator
+    }
+    
     // register MelkOutputConfigurationProvider that inserts a configuration used to read files in the project
     override configure(Binder binder) {
         super.configure(binder)
diff --git a/plugins/org.eclipse.elk.core.meta/src/org/eclipse/elk/core/meta/validation/MelkUniqueClassNameValidator.xtend b/plugins/org.eclipse.elk.core.meta/src/org/eclipse/elk/core/meta/validation/MelkUniqueClassNameValidator.xtend
new file mode 100644
index 0000000000..799788da5f
--- /dev/null
+++ b/plugins/org.eclipse.elk.core.meta/src/org/eclipse/elk/core/meta/validation/MelkUniqueClassNameValidator.xtend
@@ -0,0 +1,34 @@
+/*******************************************************************************
+ * Copyright (c) 2024 mka and others.
+ * 
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ * 
+ * SPDX-License-Identifier: EPL-2.0 
+ *******************************************************************************/
+package org.eclipse.elk.core.meta.validation
+
+import com.google.inject.Inject
+import org.eclipse.xtext.common.types.JvmDeclaredType
+import org.eclipse.xtext.common.types.TypesPackage
+import org.eclipse.xtext.naming.QualifiedName
+import org.eclipse.xtext.xbase.validation.UniqueClassNameValidator
+import org.eclipse.xtext.resource.impl.ResourceDescriptionsProvider
+
+/**
+ * Overwrites the UniqueClassNameValidator to only check for melk files in src folders. This probably
+ * prevents some special use cases where ELK is used as a library and a new melk file is created.
+ *
+ */
+class MelkUniqueClassNameValidator extends UniqueClassNameValidator {
+    
+    @Inject
+    var ResourceDescriptionsProvider resourceDescriptionsProvider;
+    
+    override doCheckUniqueName(QualifiedName name, JvmDeclaredType type) {
+        val index = resourceDescriptionsProvider.getResourceDescriptions(type.eResource())
+        val others = index.getExportedObjects(TypesPackage.Literals.JVM_DECLARED_TYPE, name, false)
+        return checkUniqueInIndex(type, others.filter[it.EObjectURI.segments.exists[it.contains("src")]])
+    }
+}