diff --git a/library/Osmocom_VTY_Functions.ttcn b/library/Osmocom_VTY_Functions.ttcn
index f118865..c7f4441 100644
--- a/library/Osmocom_VTY_Functions.ttcn
+++ b/library/Osmocom_VTY_Functions.ttcn
@@ -136,5 +136,13 @@
 	}
 }
 
+function f_vty_transceive_not_match(TELNETasp_PT pt, charstring cmd, template charstring exp_ret) {
+	var charstring ret := f_vty_transceive_ret(pt, cmd);
+	if (match(ret, exp_ret)) {
+		setverdict(fail, "Unexpected matching VTY response: ", ret);
+		self.stop;
+	}
+}
+
 
 }