Index: Gruntfile.js
===================================================================
--- Gruntfile.js	(revision 5963)
+++ Gruntfile.js	(working copy)
@@ -89,6 +89,12 @@
 				src: []
 			}
 		},
+		checkDependencies: {
+			options: {
+				packageManager: 'npm'
+			},
+			src: {}
+		},
 		copy: {
 			files: {
 				files: [
@@ -328,7 +334,7 @@
 	grunt.registerTask( 'colors', [ 'sass:colors' ] );
 
 	// Build tasks.
-	grunt.registerTask( 'src',     [ 'jsvalidate:src', 'jshint' ] );
+	grunt.registerTask( 'src',     [ 'checkDependencies', 'jsvalidate:src', 'jshint' ] );
 	grunt.registerTask( 'commit',  [ 'src', 'checktextdomain' ] );
 	grunt.registerTask( 'build',   [ 'commit', 'clean:all', 'copy:files', 'colors', 'rtlcss:core', 'cssmin:ltr', 'cssmin:rtl', 'uglify:core', 'jsvalidate:build', 'makepot' ] );
 	grunt.registerTask( 'release', [ 'build' ] );
Index: package.json
===================================================================
--- package.json	(revision 5963)
+++ package.json	(working copy)
@@ -6,6 +6,7 @@
   "description": "Forum software with a twist from the creators of WordPress.",
   "devDependencies": {
     "grunt": "~0.4.5",
+    "grunt-check-dependencies": "~0.11.2",
     "grunt-checktextdomain": "~1.0.0",
     "grunt-contrib-clean": "~0.6.0",
     "grunt-contrib-copy": "~0.8.0",