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 80f6ac4c25..e317f523aa 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
@@ -122,6 +122,9 @@ class WP_REST_Attachments_Controller extends WP_REST_Posts_Controller {
 		$type = $file['type'];
 		$file = $file['file'];
 
+		// Include image functions to get access to wp_read_image_metadata().
+		require_once ABSPATH . 'wp-admin/includes/image.php';
+
 		// use image exif/iptc data for title and caption defaults if possible
 		$image_meta = wp_read_image_metadata( $file );
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 7af003665a..0d1789885d 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-43603';
+$wp_version = '5.0-alpha-43604';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.