diff --git a/sys/contrib/ipfilter/netinet/fil.c b/sys/contrib/ipfilter/netinet/fil.c
index dc6a3be5d12..42dbc53e12d 100644
--- a/sys/contrib/ipfilter/netinet/fil.c
+++ b/sys/contrib/ipfilter/netinet/fil.c
@@ -4472,7 +4472,12 @@ frrequest(softc, unit, req, data, set, makecopy)
 	int set, makecopy;
 	caddr_t data;
 {
-	int error = 0, in, family, addrem, need_free = 0;
+	int error = 0, in, family, need_free = 0;
+	enum {	OP_UNDEF,	/* undefined */
+			OP_ADD,		/* add rule */
+			OP_REM,		/* remove rule */
+			OP_ZERO 	/* zero statistics and counters */ }
+		addrem = OP_UNDEF;
 	frentry_t frd, *fp, *f, **fprev, **ftail;
 	void *ptr, *uptr, *cptr;
 	u_int *p, *pp;
@@ -4540,11 +4545,11 @@ frrequest(softc, unit, req, data, set, makecopy)
 
 	if (req == (ioctlcmd_t)SIOCINAFR || req == (ioctlcmd_t)SIOCINIFR ||
 	    req == (ioctlcmd_t)SIOCADAFR || req == (ioctlcmd_t)SIOCADIFR)
-		addrem = 0;
+		addrem = OP_ADD;	/* Add rule */
 	else if (req == (ioctlcmd_t)SIOCRMAFR || req == (ioctlcmd_t)SIOCRMIFR)
-		addrem = 1;
+		addrem = OP_REM;		/* Remove rule */
 	else if (req == (ioctlcmd_t)SIOCZRLST)
-		addrem = 2;
+		addrem = OP_ZERO;	/* Zero statistics and counters */
 	else {
 		IPFERROR(9);
 		error = EINVAL;
@@ -4578,7 +4583,7 @@ frrequest(softc, unit, req, data, set, makecopy)
 			goto donenolock;
 		}
 
-		if (addrem == 0) {
+		if (addrem == OP_UNDEF) {
 			error = ipf_funcinit(softc, fp);
 			if (error != 0)
 				goto donenolock;
@@ -4642,7 +4647,7 @@ frrequest(softc, unit, req, data, set, makecopy)
 			 * them to be created if they don't already exit.
 			 */
 			group = FR_NAME(fp, fr_group);
-			if (addrem == 0) {
+			if (addrem == OP_UNDEF) {
 				fg = ipf_group_add(softc, group, NULL,
 						   fp->fr_flags, unit, set);
 				fp->fr_grp = fg;
@@ -4947,7 +4952,7 @@ frrequest(softc, unit, req, data, set, makecopy)
 	/*
 	 * If zero'ing statistics, copy current to caller and zero.
 	 */
-	if (addrem == 2) {
+	if (addrem == OP_ZERO) {
 		if (f == NULL) {
 			IPFERROR(27);
 			error = ESRCH;
@@ -5040,7 +5045,7 @@ frrequest(softc, unit, req, data, set, makecopy)
 	/*
 	 * Request to remove a rule.
 	 */
-	if (addrem == 1) {
+	if (addrem == OP_REM) {
 		if (f == NULL) {
 			IPFERROR(29);
 			error = ESRCH;
@@ -5106,7 +5111,7 @@ frrequest(softc, unit, req, data, set, makecopy)
 		if (fp->fr_next != NULL)
 			fp->fr_next->fr_pnext = &fp->fr_next;
 		*ftail = fp;
-		if (addrem == 0)
+		if (addrem == OP_UNDEF)
 			ipf_fixskip(ftail, fp, 1);
 
 		fp->fr_icmpgrp = NULL;