diff --git a/sys/netpfil/ipfw/ip_fw_pfil.c b/sys/netpfil/ipfw/ip_fw_pfil.c
--- a/sys/netpfil/ipfw/ip_fw_pfil.c
+++ b/sys/netpfil/ipfw/ip_fw_pfil.c
@@ -371,6 +371,8 @@
 	}
 
 	ipfw = ipfw_chk(&args);
+	if (!mem)
+		*p.m = args.m;
 
 	ret = PFIL_PASS;
 	switch (ipfw) {