Index: Gruntfile.js
===================================================================
--- Gruntfile.js	(revision 47108)
+++ Gruntfile.js	(working copy)
@@ -1099,8 +1099,9 @@
 				files: [
 					SOURCE_DIR + '**',
 					'!' + SOURCE_DIR + 'js/**/*.js',
-					// Ignore version control directories.
-					'!' + SOURCE_DIR + '**/.{svn,git}/**'
+					// Ignore version control directories and build files.
+					'!' + SOURCE_DIR + '**/.{svn,git}/**',
+					'!' + SOURCE_DIR + '**/node_modules/**',
 				],
 				tasks: ['clean:dynamic', 'copy:dynamic'],
 				options: {