diff --git a/wp-includes/pluggable.php b/wp-includes/pluggable.php
index b8bed355fc..4a4776b264 100644
--- a/wp-includes/pluggable.php
+++ b/wp-includes/pluggable.php
@@ -2535,7 +2535,7 @@ function get_avatar( $id_or_email, $size = 96, $default = '', $alt = '', $args =
 		"<img alt='%s' src='%s' srcset='%s' class='%s' height='%d' width='%d' %s/>",
 		esc_attr( $args['alt'] ),
 		esc_url( $url ),
-		esc_attr( "$url2x 2x" ),
+		esc_url( $url2x ) . ' 2x',
 		esc_attr( join( ' ', $class ) ),
 		(int) $args['height'],
 		(int) $args['width'],
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 117e80601f..4b74c79896 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.9-alpha-41154';
+$wp_version = '4.9-alpha-41156';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.