diff --git a/sys/src/cmd/pc.y b/sys/src/cmd/pc.y
index 1abb328df..5bbea3212 100644
--- a/sys/src/cmd/pc.y
+++ b/sys/src/cmd/pc.y
@@ -1065,4 +1065,6 @@ main(int argc, char **argv)
 	if(in == nil) sysfatal("Bfdopen: %r");
 	extern void yyparse(void);
 	yyparse();
+	extern int yynerrs;
+	exits(yynerrs ? "error" : nil);
 }