Index: contrib/bind9/lib/dns/rbtdb.c
===================================================================
--- contrib/bind9/lib/dns/rbtdb.c	(revision 228802)
+++ contrib/bind9/lib/dns/rbtdb.c	(working copy)
@@ -278,6 +278,7 @@
 #define RDATASET_ATTR_RESIGN            0x0020
 #define RDATASET_ATTR_STATCOUNT         0x0040
 #define RDATASET_ATTR_OPTOUT		0x0080
+#define RDATASET_ATTR_NEGATIVE		0x0100
 
 typedef struct acache_cbarg {
 	dns_rdatasetadditional_t        type;
@@ -316,6 +317,8 @@
 	(((header)->attributes & RDATASET_ATTR_RESIGN) != 0)
 #define OPTOUT(header) \
 	(((header)->attributes & RDATASET_ATTR_OPTOUT) != 0)
+#define NEGATIVE(header) \
+	(((header)->attributes & RDATASET_ATTR_NEGATIVE) != 0)
 
 #define DEFAULT_NODE_LOCK_COUNT         7       /*%< Should be prime. */
 
@@ -4620,7 +4623,7 @@
 			      rdataset);
 		if (need_headerupdate(found, search.now))
 			update = found;
-		if (foundsig != NULL) {
+		if (!NEGATIVE(found) && foundsig != NULL) {
 			bind_rdataset(search.rbtdb, node, foundsig, search.now,
 				      sigrdataset);
 			if (need_headerupdate(foundsig, search.now))
@@ -5249,7 +5252,7 @@
 	}
 	if (found != NULL) {
 		bind_rdataset(rbtdb, rbtnode, found, now, rdataset);
-		if (foundsig != NULL)
+		if (!NEGATIVE(found) && foundsig != NULL)
 			bind_rdataset(rbtdb, rbtnode, foundsig, now,
 				      sigrdataset);
 	}
Index: contrib/bind9/bin/named/query.c
===================================================================
--- contrib/bind9/bin/named/query.c	(revision 228802)
+++ contrib/bind9/bin/named/query.c	(working copy)
@@ -1280,11 +1280,9 @@
 			goto addname;
 		if (result == DNS_R_NCACHENXRRSET) {
 			dns_rdataset_disassociate(rdataset);
-			/*
-			 * Negative cache entries don't have sigrdatasets.
-			 */
-			INSIST(sigrdataset == NULL ||
-			       ! dns_rdataset_isassociated(sigrdataset));
+			if (sigrdataset != NULL &&
+			    dns_rdataset_isassociated(sigrdataset))
+				dns_rdataset_disassociate(sigrdataset);
 		}
 		if (result == ISC_R_SUCCESS) {
 			mname = NULL;
@@ -1325,8 +1323,9 @@
 			goto addname;
 		if (result == DNS_R_NCACHENXRRSET) {
 			dns_rdataset_disassociate(rdataset);
-			INSIST(sigrdataset == NULL ||
-			       ! dns_rdataset_isassociated(sigrdataset));
+			if (sigrdataset != NULL &&
+			    dns_rdataset_isassociated(sigrdataset))
+				dns_rdataset_disassociate(sigrdataset);
 		}
 		if (result == ISC_R_SUCCESS) {
 			mname = NULL;
@@ -1775,10 +1774,8 @@
 		goto setcache;
 	if (result == DNS_R_NCACHENXRRSET) {
 		dns_rdataset_disassociate(rdataset);
-		/*
-		 * Negative cache entries don't have sigrdatasets.
-		 */
-		INSIST(! dns_rdataset_isassociated(sigrdataset));
+		if (dns_rdataset_isassociated(sigrdataset))
+			dns_rdataset_disassociate(sigrdataset);
 	}
 	if (result == ISC_R_SUCCESS) {
 		/* Remember the result as a cache */