diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java
index 46283bd5219..1697054a84a 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java
@@ -8123,6 +8123,39 @@ public class AST2TemplateTests extends AST2TestBase {
 		assertEquals(1, num.longValue());
 	}
 
+	//	template <int> 
+	//	struct A {
+	//	    void waldo();
+	//	};
+	//	    
+	//	template <typename> 
+	//	struct traits {
+	//	  enum {
+	//	    E = 1,
+	//	  };
+	//	};
+	//
+	//	template <typename T> 
+	//	struct L {
+	//	  enum { 
+	//	      X = traits<T>::E & 1
+	//	  };
+	//	};
+	//	    
+	//	template <typename T> 
+	//	struct B : A<L<T>::X> {
+	//	    using A<L<T>::X>::waldo;
+	//	};
+	//
+	//	class M : public B<M> {};
+	//
+	//	void bar(B<M>& v) {
+	//	    v.waldo();
+	//	}
+	public void testArgumentDependentLookupForEnumeration_506170() throws Exception {
+		parseAndCheckBindings();
+	}
+
 	//	template <int...> struct A {};
 	//	template <int... I> void foo(A<I...>);
 	//	int main() {
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPSemantics.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPSemantics.java
index 77fed825f64..d75ed6a77c4 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPSemantics.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPSemantics.java
@@ -787,14 +787,20 @@ public class CPPSemantics {
             if (handled.containsKey(t))
             	return;
             handled.put(t);
-
-    		IBinding owner= ((IBinding) t).getOwner();
-    		if (owner instanceof ICPPClassType) {
-    			getAssociatedScopes((IType) owner, namespaces, friendFns, handled, tu,
-    					false /* do not look at base classes of the enclosing class */);
-    		} else {
-    			getAssociatedNamespaceScopes(getContainingNamespaceScope((IBinding) t, tu), namespaces);
-    		}
+            
+            if (t instanceof IEnumeration) {
+            	// [basic.lookup.argdep] p2.3: an enumeration's only associated namespace
+            	// is the innermost enclosing namespace of its declaration.
+            	getAssociatedNamespaceScopes(getContainingNamespaceScope((IBinding) t, tu), namespaces);
+            } else {
+	    		IBinding owner= ((IBinding) t).getOwner();
+	    		if (owner instanceof ICPPClassType) {
+	    			getAssociatedScopes((IType) owner, namespaces, friendFns, handled, tu,
+	    					false /* do not look at base classes of the enclosing class */);
+	    		} else {
+	    			getAssociatedNamespaceScopes(getContainingNamespaceScope((IBinding) t, tu), namespaces);
+	    		}
+            }
     	}
 		if (t instanceof ICPPClassType && !(t instanceof ICPPClassTemplate)) {
 			ICPPClassType ct= (ICPPClassType) t;