Improved failure message
diff --git a/tests/org.eclipse.jface.tests.databinding/src/org/eclipse/core/tests/databinding/UpdateStrategyTest.java b/tests/org.eclipse.jface.tests.databinding/src/org/eclipse/core/tests/databinding/UpdateStrategyTest.java
index d47952e..351f668 100644
--- a/tests/org.eclipse.jface.tests.databinding/src/org/eclipse/core/tests/databinding/UpdateStrategyTest.java
+++ b/tests/org.eclipse.jface.tests.databinding/src/org/eclipse/core/tests/databinding/UpdateStrategyTest.java
@@ -291,7 +291,9 @@
 		assertNotNull("converter not null", converter);
 		assertEquals("fromType [" + fromType + "]" , fromType, converter.getFromType());
 		assertEquals("toType [" + toType + "]", toType, converter.getToType());
-		assertTrue("converter instanceof " + converterType, converterType.isInstance(converter));
+		assertTrue("converter should be instanceof " + converterType
+				+ " but was instanceof " + converter.getClass(), converterType
+				.isInstance(converter));
 	}
 	
 	class UpdateStrategyStub extends UpdateValueStrategy {