diff --git a/sys/net/if.c b/sys/net/if.c
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -3241,6 +3241,9 @@
 	int error;
 	int oldflags = ifp->if_flags;
 
+	if (pswitch == 0 && ifp->if_pcount == 0)
+		return (0);
+
 	error = if_setflag(ifp, IFF_PROMISC, IFF_PPROMISC,
 			   &ifp->if_pcount, pswitch);
 	/* If promiscuous mode status has changed, log a message */