diff --git a/maven-core/src/test/java/org/apache/maven/project/PomConstructionTest.java b/maven-core/src/test/java/org/apache/maven/project/PomConstructionTest.java
index c7daaf7b55..5fc7459db8 100644
--- a/maven-core/src/test/java/org/apache/maven/project/PomConstructionTest.java
+++ b/maven-core/src/test/java/org/apache/maven/project/PomConstructionTest.java
@@ -173,7 +173,7 @@ public class PomConstructionTest
 
     }
 
-    /** MNG-4005 */
+    /** MNG-4005: postponed to 3.1
     public void testValidationErrorUponNonUniqueDependencyKey()
         throws Exception
     {
@@ -229,6 +229,7 @@ public class PomConstructionTest
             // expected
         }
     }
+    */
 
     public void testDuplicateDependenciesCauseLastDeclarationToBePickedInLenientMode()
         throws Exception
diff --git a/maven-model-builder/src/main/java/org/apache/maven/model/validation/DefaultModelValidator.java b/maven-model-builder/src/main/java/org/apache/maven/model/validation/DefaultModelValidator.java
index 914bc30d05..b38ec1a40a 100644
--- a/maven-model-builder/src/main/java/org/apache/maven/model/validation/DefaultModelValidator.java
+++ b/maven-model-builder/src/main/java/org/apache/maven/model/validation/DefaultModelValidator.java
@@ -299,6 +299,7 @@ public class DefaultModelValidator
                                        ModelBuildingRequest request )
     {
         Severity errOn30 = getSeverity( request, ModelBuildingRequest.VALIDATION_LEVEL_MAVEN_3_0 );
+        Severity errOn31 = getSeverity( request, ModelBuildingRequest.VALIDATION_LEVEL_MAVEN_3_1 );
 
         Map<String, Dependency> index = new HashMap<String, Dependency>();
 
@@ -340,7 +341,7 @@ public class DefaultModelValidator
                             + StringUtils.defaultString( dependency.getVersion(), "(?)" );
                 }
 
-                addViolation( problems, errOn30, prefix + ".(groupId:artifactId:type:classifier)", null,
+                addViolation( problems, errOn31, prefix + ".(groupId:artifactId:type:classifier)", null,
                               "must be unique: " + key + " -> " + msg );
             }
             else