diff --git a/library/Osmocom_Types.ttcn b/library/Osmocom_Types.ttcn
index ab5c098d0..1766a405c 100644
--- a/library/Osmocom_Types.ttcn
+++ b/library/Osmocom_Types.ttcn
@@ -91,7 +91,7 @@ function bool2bit_tmpl(template boolean inp) return template BIT1 {
 			return '0'B;
 		}
 	}
-	setverdict(fail, "Unsupported template");
+	setverdict(fail, "Unsupported template", inp);
 	self.stop;
 }