diff --git a/servers/slapd/back-dnssrv/compare.c b/servers/slapd/back-dnssrv/compare.c
index 0d1beaa936..15d2a089b2 100644
--- a/servers/slapd/back-dnssrv/compare.c
+++ b/servers/slapd/back-dnssrv/compare.c
@@ -25,6 +25,9 @@ dnssrv_back_compare(
 	AttributeAssertion *ava
 )
 {
-	return dnssrv_back_request( be, conn, op, dn, ndn,
-		0, NULL, NULL, 0 );
+	assert( get_manageDSAit( op ) );
+
+	/* not implemented */
+
+	return LDAP_OTHER;
 }
diff --git a/servers/slapd/back-dnssrv/init.c b/servers/slapd/back-dnssrv/init.c
index b75cced1b6..452a872b67 100644
--- a/servers/slapd/back-dnssrv/init.c
+++ b/servers/slapd/back-dnssrv/init.c
@@ -55,7 +55,7 @@ dnssrv_back_initialize(
 	bi->bi_op_bind = dnssrv_back_bind;
 	bi->bi_op_unbind = 0;
 	bi->bi_op_search = dnssrv_back_search;
-	bi->bi_op_compare = dnssrv_back_compare;
+	bi->bi_op_compare = 0 /* dnssrv_back_compare */;
 	bi->bi_op_modify = 0;
 	bi->bi_op_modrdn = 0;
 	bi->bi_op_add = 0;