diff --git a/src/wp-includes/class-wp-comment-query.php b/src/wp-includes/class-wp-comment-query.php
index 4447b1169b..9a481b1bda 100644
--- a/src/wp-includes/class-wp-comment-query.php
+++ b/src/wp-includes/class-wp-comment-query.php
@@ -1036,13 +1036,19 @@ protected function fill_descendants( $comments ) {
 			$child_ids           = array();
 			$uncached_parent_ids = array();
 			$_parent_ids         = $levels[ $level ];
-			foreach ( $_parent_ids as $parent_id ) {
-				$cache_key        = "get_comment_child_ids:$parent_id:$key:$last_changed";
-				$parent_child_ids = wp_cache_get( $cache_key, 'comment' );
-				if ( false !== $parent_child_ids ) {
-					$child_ids = array_merge( $child_ids, $parent_child_ids );
-				} else {
-					$uncached_parent_ids[] = $parent_id;
+			if ( $_parent_ids ) {
+				$cache_keys = array();
+				foreach ( $_parent_ids as $parent_id ) {
+					$cache_keys[ $parent_id ] = "get_comment_child_ids:$parent_id:$key:$last_changed";
+				}
+				$cache_data = wp_cache_get_multiple( array_values( $cache_keys ), 'comment-queries' );
+				foreach ( $_parent_ids as $parent_id ) {
+					$parent_child_ids = $cache_data[ $cache_keys[ $parent_id ] ];
+					if ( false !== $parent_child_ids ) {
+						$child_ids = array_merge( $child_ids, $parent_child_ids );
+					} else {
+						$uncached_parent_ids[] = $parent_id;
+					}
 				}
 			}