Index: Gruntfile.js
===================================================================
--- Gruntfile.js	(revision 43773)
+++ Gruntfile.js	(working copy)
@@ -603,7 +603,8 @@
 				files: {
 					src: [
 						BUILD_DIR + 'wp-{admin,includes}/**/*.js',
-						BUILD_DIR + 'wp-content/themes/twenty*/**/*.js'
+						BUILD_DIR + 'wp-content/themes/twenty*/**/*.js',
+						'!' + BUILD_DIR + 'wp-includes/js/dist/vendor/*.js'
 					]
 				}
 			}