Index: contrib/bind9/lib/dns/rbtdb.c
===================================================================
--- contrib/bind9/lib/dns/rbtdb.c	(revision 228188)
+++ contrib/bind9/lib/dns/rbtdb.c	(revision 228189)
@@ -5053,7 +5053,7 @@
 			      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))
@@ -5685,7 +5685,7 @@
 	}
 	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 228188)
+++ contrib/bind9/bin/named/query.c	(revision 228189)
@@ -1393,11 +1393,9 @@
 			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;
@@ -1438,8 +1436,9 @@
 			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;
@@ -1889,10 +1888,8 @@
 		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 */