diff --git a/lib/dns/adb.c b/lib/dns/adb.c
index 59b6d56e1c..cf76f62044 100644
--- a/lib/dns/adb.c
+++ b/lib/dns/adb.c
@@ -1717,10 +1717,44 @@ dns_adb_marklame(dns_adb_t *adb, dns_adbaddrinfo_t *addr, dns_name_t *zone,
 	zi->lame_timer = expire_time;
 
 	bucket = addr->entry->lock_bucket;
-
 	LOCK(&adb->entrylocks[bucket]);
 	ISC_LIST_PREPEND(addr->entry->zoneinfo, zi, link);
 	UNLOCK(&adb->entrylocks[bucket]);
 
 	return (ISC_R_SUCCESS);
 }
+
+void
+dns_adb_adjustgoodness(dns_adb_t *adb, dns_adbaddrinfo_t *addr,
+		       int goodness_adjustment)
+{
+	int bucket;
+	int old_goodness, new_goodness;
+
+	REQUIRE(DNS_ADBADDRINFO_VALID(addr));
+
+	if (goodness_adjustment == 0)
+		return;
+
+	bucket = addr->entry->lock_bucket;
+	LOCK(&adb->entrylocks[bucket]);
+
+	old_goodness = addr->entry->goodness;
+
+	if (goodness_adjustment > 0) {
+		if (old_goodness > INT_MAX - goodness_adjustment)
+			new_goodness = INT_MAX;
+		else
+			new_goodness = old_goodness + goodness_adjustment;
+	} else {
+		if (old_goodness < INT_MIN - goodness_adjustment)
+			new_goodness = INT_MAX;
+		else
+			new_goodness = old_goodness + goodness_adjustment;
+	}
+
+	addr->entry->goodness = new_goodness;
+
+	UNLOCK(&adb->entrylocks[bucket]);
+}
+
diff --git a/lib/dns/include/dns/adb.h b/lib/dns/include/dns/adb.h
index c0503fa12b..4326eb105f 100644
--- a/lib/dns/include/dns/adb.h
+++ b/lib/dns/include/dns/adb.h
@@ -387,6 +387,23 @@ dns_adb_marklame(dns_adb_t *adb, dns_adbaddrinfo_t *addr, dns_name_t *zone,
  *	ISC_R_NOMEMORY		-- could not mark address as lame.
  */
 
+void
+dns_adb_adjustgoodness(dns_adb_t *adb, dns_adbaddrinfo_t *addr,
+		       int goodness_adjustment);
+/*
+ * Increase or decrease the address's goodness value.
+ *
+ * Requires:
+ *
+ *	adb be valid.
+ *
+ *	addr be valid.
+ *
+ * Note:
+ *
+ *	Goodness values are silently clamped to INT_MAX and INT_MIN.
+ */
+
 /*
  * XXX Need functions/macros to:
  *