diff --git a/src/check.c b/src/check.c
index 0fab0d4..ba9c1f3 100644
--- a/src/check.c
+++ b/src/check.c
@@ -1851,7 +1851,7 @@
 		memprintf(err, "'%s' : missing value", args[*cur_arg]);
 		goto error;
 	}
-	newsrv->check.mux_proto = get_mux_proto(ist2(args[*cur_arg + 1], strlen(args[*cur_arg + 1])));
+	newsrv->check.mux_proto = get_mux_proto(ist(args[*cur_arg + 1]));
 	if (!newsrv->check.mux_proto) {
 		memprintf(err, "'%s' :  unknown MUX protocol '%s'", args[*cur_arg], args[*cur_arg+1]);
 		goto error;