diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2CPPTests.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2CPPTests.java
index 581a80d4a2a..5c61f54be2b 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2CPPTests.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2CPPTests.java
@@ -1748,6 +1748,21 @@ public class AST2CPPTests extends AST2TestBase {
 		// This assertion fails because conv is the copy ctor A(const A&), not the conversion operator B::operator A()
 		assertSame(oper, conv);
 	}
+	
+	//	struct S {
+	//	  operator int() &;
+	//	  operator int() &&;
+	//	};
+	//	
+	//	void waldo(int);
+	//	
+	//	int main() {
+	//	  S s;
+	//	  waldo(s);  // ERROR
+	//	}
+	public void testOverloadedRefQualifiedConversionOperators_506728() throws Exception {
+		parseAndCheckBindings();
+	}
 
 	// namespace A { int x; }
 	// namespace B = A;
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/Conversions.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/Conversions.java
index c6f2d956779..8379a771290 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/Conversions.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/Conversions.java
@@ -856,7 +856,8 @@ public class Conversions {
 				if (isExplicitConversion /** && !direct **/)
 					continue;
 
-				final IType returnType = op.getType().getReturnType();
+				ICPPFunctionType functionType = op.getType();
+				final IType returnType = functionType.getReturnType();
 				IType uqReturnType= getNestedType(returnType, TDEF | ALLCVQ);
 				Cost c2= checkImplicitConversionSequence(target, uqReturnType, valueCategoryFromReturnType(uqReturnType), UDCMode.FORBIDDEN, Context.ORDINARY, point);
 				if (c2.converts()) {
@@ -866,7 +867,11 @@ public class Conversions {
 					final Cost udcCost = isReferenceCompatible(getNestedType(implicitType, TDEF | REF), source, true, point);
 					if (udcCost != null) {
 						// Make sure top-level cv-qualifiers are compared
-						udcCost.setReferenceBinding(ReferenceBinding.LVALUE_REF);
+						if (functionType.hasRefQualifier() && functionType.isRValueReference()) {
+							udcCost.setReferenceBinding(ReferenceBinding.RVALUE_REF_BINDS_RVALUE);
+						} else {
+							udcCost.setReferenceBinding(ReferenceBinding.LVALUE_REF);
+						}
 						FunctionCost c1= new FunctionCost(op, udcCost, point);
 						int cmp= c1.compareTo(null, cost1);
 						if (cmp <= 0) {