diff --git a/compiler/RAPID_CodeGen.jrag b/compiler/RAPID_CodeGen.jrag
index 9910048f17c5b7885940a45f92779a74411da3b5..9759b946d0af1e16dc1bac89e00e0fd19b29571d 100644
--- a/compiler/RAPID_CodeGen.jrag
+++ b/compiler/RAPID_CodeGen.jrag
@@ -194,7 +194,7 @@ aspect RAPID_CodeGen {
 	}
 
 	public String Type.RAPID_AddType(RAPID_env env, String name) {
-		throw new UnsupportedOperationException();
+		throw new UnsupportedOperationException("RAPID_AddType not implemented for "+getClass().getSimpleName());
 	}
 
 	public String StructType.RAPID_AddType(RAPID_env env, String name) {