Index: modeshape-jcr/src/main/java/org/modeshape/jcr/JcrSession.java
===================================================================
--- modeshape-jcr/src/main/java/org/modeshape/jcr/JcrSession.java	(revision 1724)
+++ modeshape-jcr/src/main/java/org/modeshape/jcr/JcrSession.java	(working copy)
@@ -874,11 +874,6 @@ class JcrSession implements Session {
             throw new VersionException(JcrI18n.nodeIsCheckedIn.text(newParentNode.getPath()));
         }
 
-        String newNodeNameAsString = newNodeName.getString(executionContext.getNamespaceRegistry());
-        if (newParentNode.hasNode(newNodeName.getString(executionContext.getNamespaceRegistry()))) {
-            throw new ItemExistsException(JcrI18n.childNodeAlreadyExists.text(newNodeNameAsString, newParentNode.getPath()));
-        }
-
         newParentNode.editor().moveToBeChild(sourceNode, newNodeName.getName());
     }
 
Index: modeshape-jcr/src/test/resources/repositoryStubImpl.properties
===================================================================
--- modeshape-jcr/src/test/resources/repositoryStubImpl.properties	(revision 1724)
+++ modeshape-jcr/src/test/resources/repositoryStubImpl.properties	(working copy)
@@ -51,6 +51,9 @@ javax.jcr.tck.NodeOrderableChildNodesTest.testOrderBeforeUnsupportedRepositoryOp
 javax.jcr.tck.SaveTest.nodetype=nt\:query
 javax.jcr.tck.SetPropertyAssumeTypeTest.nodetype=modetest\:setPropertyAssumeTypeTest
 
+# Session test that requires a node that doesn't allow two children with the same name
+javax.jcr.tck.SessionTest.testMoveItemExistsException.nodetype2=modetest\:noSameNameSibs
+
 # version test types
 javax.jcr.tck.versionableNodeType=modetest\:versionableUnstructured
 javax.jcr.tck.propertyValue=31337