diff --git a/library/GTP_Templates.ttcn b/library/GTP_Templates.ttcn
index d0a87e3..018f6da 100644
--- a/library/GTP_Templates.ttcn
+++ b/library/GTP_Templates.ttcn
@@ -464,7 +464,8 @@
 				}
 			}
 		}
-		setverdict(fail);
+		setverdict(fail, "Could not extract protocol payload from protocol ", protocol);
+		mtc.stop;
 		return ''O;
 	}