Index: sys/netgraph/ng_nat.c
===================================================================
--- sys/netgraph/ng_nat.c
+++ sys/netgraph/ng_nat.c
@@ -365,15 +365,17 @@
 		    {
 			struct ng_nat_mode *const mode = 
 			    (struct ng_nat_mode *)msg->data;
+			unsigned int flags, mask;
 
 			if (msg->header.arglen < sizeof(*mode)) {
 				error = EINVAL;
 				break;
 			}
-			
-			if (LibAliasSetMode(priv->lib, 
-			    ng_nat_translate_flags(mode->flags),
-			    ng_nat_translate_flags(mode->mask)) < 0) {
+
+			flags = ng_nat_translate_flags(mode->flags);
+			mask = ng_nat_translate_flags(mode->mask);
+			if ((LibAliasSetMode(priv->lib, flags, mask) & mask) !=
+			    (flags & mask)) {
 				error = ENOMEM;
 				break;
 			}
Index: sys/netinet/libalias/alias_db.c
===================================================================
--- sys/netinet/libalias/alias_db.c
+++ sys/netinet/libalias/alias_db.c
@@ -2575,14 +2575,16 @@
 				 * do a probe for flag values) */
 )
 {
-	int res = -1;
+	unsigned int res;
 
 	LIBALIAS_LOCK(la);
 /* Enable logging? */
 	if (flags & mask & PKT_ALIAS_LOG) {
 		/* Do the enable */
-		if (InitPacketAliasLog(la) == ENOMEM)
+		if (InitPacketAliasLog(la) == ENOMEM) {
+			res = la->packetAliasMode;
 			goto getout;
+		}
 	} else
 /* _Disable_ logging? */
 	if (~flags & mask & PKT_ALIAS_LOG) {