diff --git a/wp-includes/post.php b/wp-includes/post.php
index b46d97bf14..93a1b59adf 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -6277,6 +6277,8 @@ function wp_update_attachment_metadata( $attachment_id, $data ) {
  * @return string|false Attachment URL, otherwise false.
  */
 function wp_get_attachment_url( $attachment_id = 0 ) {
+	global $pagenow;
+
 	$attachment_id = (int) $attachment_id;
 
 	$post = get_post( $attachment_id );
@@ -6319,7 +6321,7 @@ function wp_get_attachment_url( $attachment_id = 0 ) {
 	}
 
 	// On SSL front end, URLs should be HTTPS.
-	if ( is_ssl() && ! is_admin() && 'wp-login.php' !== $GLOBALS['pagenow'] ) {
+	if ( is_ssl() && ! is_admin() && 'wp-login.php' !== $pagenow ) {
 		$url = set_url_scheme( $url );
 	}
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 700587f389..5677110ba3 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.7-beta3-50401';
+$wp_version = '5.7-beta3-50406';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.