diff --git a/wp-admin/includes/post.php b/wp-admin/includes/post.php
index ab50c27d94..eca583a2ec 100644
--- a/wp-admin/includes/post.php
+++ b/wp-admin/includes/post.php
@@ -1154,35 +1154,6 @@ function wp_edit_attachments_query_vars( $q = false ) {
 	return $q;
 }
 
-/**
- * Filter the SQL clauses of an attachment query to include filenames.
- *
- * @since 4.7.0
- * @access private
- *
- * @global wpdb $wpdb WordPress database abstraction object.
- *
- * @param array $clauses An array including WHERE, GROUP BY, JOIN, ORDER BY,
- *                       DISTINCT, fields (SELECT), and LIMITS clauses.
- * @return array The modified clauses.
- */
-function _filter_query_attachment_filenames( $clauses ) {
-	global $wpdb;
-	remove_filter( 'posts_clauses', __FUNCTION__ );
-
-	// Add a LEFT JOIN of the postmeta table so we don't trample existing JOINs.
-	$clauses['join'] .= " LEFT JOIN {$wpdb->postmeta} AS sq1 ON ( {$wpdb->posts}.ID = sq1.post_id AND sq1.meta_key = '_wp_attached_file' )";
-
-	$clauses['groupby'] = "{$wpdb->posts}.ID";
-
-	$clauses['where'] = preg_replace(
-		"/\({$wpdb->posts}.post_content (NOT LIKE|LIKE) (\'[^']+\')\)/",
-		"$0 OR ( sq1.meta_value $1 $2 )",
-		$clauses['where'] );
-
-	return $clauses;
-}
-
 /**
  * Executes a query for attachments. An array of WP_Query arguments
  * can be passed in, which will override the arguments set by this function.
diff --git a/wp-includes/post.php b/wp-includes/post.php
index c81f5c589e..d9c64f5bfe 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -6188,3 +6188,32 @@ function wp_add_trashed_suffix_to_post_name_for_post( $post ) {
 	clean_post_cache( $post->ID );
 	return $post_name;
 }
+
+/**
+ * Filter the SQL clauses of an attachment query to include filenames.
+ *
+ * @since 4.7.0
+ * @access private
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param array $clauses An array including WHERE, GROUP BY, JOIN, ORDER BY,
+ *                       DISTINCT, fields (SELECT), and LIMITS clauses.
+ * @return array The modified clauses.
+ */
+function _filter_query_attachment_filenames( $clauses ) {
+	global $wpdb;
+	remove_filter( 'posts_clauses', __FUNCTION__ );
+
+	// Add a LEFT JOIN of the postmeta table so we don't trample existing JOINs.
+	$clauses['join'] .= " LEFT JOIN {$wpdb->postmeta} AS sq1 ON ( {$wpdb->posts}.ID = sq1.post_id AND sq1.meta_key = '_wp_attached_file' )";
+
+	$clauses['groupby'] = "{$wpdb->posts}.ID";
+
+	$clauses['where'] = preg_replace(
+		"/\({$wpdb->posts}.post_content (NOT LIKE|LIKE) (\'[^']+\')\)/",
+		"$0 OR ( sq1.meta_value $1 $2 )",
+		$clauses['where'] );
+
+	return $clauses;
+}
diff --git a/wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php b/wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php
index f0055ee4b3..8f0318adbe 100644
--- a/wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php
+++ b/wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php
@@ -47,6 +47,11 @@ class WP_REST_Attachments_Controller extends WP_REST_Posts_Controller {
 			}
 		}
 
+		// Filter query clauses to include filenames.
+		if ( isset( $query_args['s'] ) ) {
+			add_filter( 'posts_clauses', '_filter_query_attachment_filenames' );
+		}
+
 		return $query_args;
 	}
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 00ef2f560e..6161c3546c 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7.1-alpha-39628';
+$wp_version = '4.7.1-alpha-39629';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.