diff --git a/wp-includes/meta.php b/wp-includes/meta.php
index b57e761f46..bcfc847e80 100644
--- a/wp-includes/meta.php
+++ b/wp-includes/meta.php
@@ -294,14 +294,17 @@ function update_metadata($meta_type, $object_id, $meta_key, $meta_value, $prev_v
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
- * @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
- * @param int $object_id ID of the object metadata is for
- * @param string $meta_key Metadata key
- * @param mixed $meta_value Optional. Metadata value. Must be serializable if non-scalar. If specified, only delete metadata entries
- * 		with this value. Otherwise, delete all entries with the specified meta_key.
- * @param bool $delete_all Optional, default is false. If true, delete matching metadata entries
- * 		for all objects, ignoring the specified object_id. Otherwise, only delete matching
- * 		metadata entries for the specified object_id.
+ * @param string $meta_type  Type of object metadata is for (e.g., comment, post, or user)
+ * @param int    $object_id  ID of the object metadata is for
+ * @param string $meta_key   Metadata key
+ * @param mixed  $meta_value Optional. Metadata value. Must be serializable if non-scalar. If specified, only delete
+ *                           metadata entries with this value. Otherwise, delete all entries with the specified meta_key.
+ *                           Pass `null, `false`, or an empty string to skip this check. (For backward compatibility,
+ *                           it is not possible to pass an empty string to delete those entries with an empty string
+ *                           for a value.)
+ * @param bool   $delete_all Optional, default is false. If true, delete matching metadata entries for all objects,
+ *                           ignoring the specified object_id. Otherwise, only delete matching metadata entries for
+ *                           the specified object_id.
  * @return bool True on successful delete, false on failure.
  */
 function delete_metadata($meta_type, $object_id, $meta_key, $meta_value = '', $delete_all = false) {
@@ -356,7 +359,7 @@ function delete_metadata($meta_type, $object_id, $meta_key, $meta_value = '', $d
 	if ( !$delete_all )
 		$query .= $wpdb->prepare(" AND $type_column = %d", $object_id );
 
-	if ( $meta_value )
+	if ( '' !== $meta_value && null !== $meta_value && false !== $meta_value )
 		$query .= $wpdb->prepare(" AND meta_value = %s", $meta_value );
 
 	$meta_ids = $wpdb->get_col( $query );
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 2cbebc9a82..54b9775bbe 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.3-alpha-32330';
+$wp_version = '4.3-alpha-32331';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.