diff --git a/sys/netpfil/ipfw/ip_fw_sockopt.c b/sys/netpfil/ipfw/ip_fw_sockopt.c
index 107c4b889962..7ed4c1d055c3 100644
--- a/sys/netpfil/ipfw/ip_fw_sockopt.c
+++ b/sys/netpfil/ipfw/ip_fw_sockopt.c
@@ -1531,7 +1531,7 @@ check_ipfw_rule_body(ipfw_insn *cmd, int cmd_len, struct rule_check_info *ci)
 		case O_IP_SRC_MASK:
 		case O_IP_DST_MASK:
 			/* only odd command lengths */
-			if ( !(cmdlen & 1) || cmdlen > 31)
+			if ((cmdlen & 1) == 0)
 				goto bad_size;
 			break;