diff --git a/src/wp-includes/class-wp-list-util.php b/src/wp-includes/class-wp-list-util.php
index 656035529186e..cbc9685560eef 100644
--- a/src/wp-includes/class-wp-list-util.php
+++ b/src/wp-includes/class-wp-list-util.php
@@ -165,9 +165,9 @@ public function pluck( $field, $index_key = null ) {
 			 */
 			foreach ( $this->output as $key => $value ) {
 				if ( is_object( $value ) ) {
-					$newlist[ $key ] = $value->$field;
+					$newlist[ $key ] = $value->$field ?? null;
 				} elseif ( is_array( $value ) ) {
-					$newlist[ $key ] = $value[ $field ];
+					$newlist[ $key ] = $value[ $field ] ?? null;
 				} else {
 					_doing_it_wrong(
 						__METHOD__,