diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index 86e45e12d3..3098fa525e 100644
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -221,7 +221,7 @@ walkdef(Node *n)
 	if(n->op == ONONAME) {
 		if(!n->diag) {
 			n->diag = 1;
-			yyerror("undefined: %S", n->sym);
+			yyerrorl(n->lineno, "undefined: %S", n->sym);
 		}
 		return;
 	}