diff --git a/sys/src/cmd/ip/pppoe.c b/sys/src/cmd/ip/pppoe.c
index 9fcd8c05d..6cd3f2570 100644
--- a/sys/src/cmd/ip/pppoe.c
+++ b/sys/src/cmd/ip/pppoe.c
@@ -358,6 +358,7 @@ wantoffer(uchar *pkt)
 	acname = copy(s, len);
 	if(wantac && strcmp(acname, wantac) != 0){
 		free(acname);
+		acname = nil;
 		return bad("wrong ac name");
 	}