diff --git a/build/gulpfile.common.js b/build/gulpfile.common.js
index 838f71d4ee7..dfbcc8942c5 100644
--- a/build/gulpfile.common.js
+++ b/build/gulpfile.common.js
@@ -3,6 +3,8 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
+/*global require,exports,__dirname,Buffer,setTimeout*/
+
 var path = require('path');
 var gulp = require('gulp');
 var sourcemaps = require('gulp-sourcemaps');
@@ -12,7 +14,6 @@ var uglify = require('gulp-uglify');
 var es = require('event-stream');
 var concat = require('gulp-concat');
 var File = require('vinyl');
-var underscore = require('underscore');
 var bundle = require('./lib/bundle');
 var util = require('./lib/util');
 var root = path.dirname(__dirname);
diff --git a/build/gulpfile.editor.js b/build/gulpfile.editor.js
index b8bc5f74148..f0f4761c754 100644
--- a/build/gulpfile.editor.js
+++ b/build/gulpfile.editor.js
@@ -3,9 +3,10 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
+/*global require,__dirname*/
+
 var gulp = require('gulp');
 var path = require('path');
-var rename = require('gulp-rename');
 var filter = require('gulp-filter');
 var _ = require('underscore');
 var es = require('event-stream');
diff --git a/build/gulpfile.extensions.js b/build/gulpfile.extensions.js
index 0feb6d74186..db363a5265e 100644
--- a/build/gulpfile.extensions.js
+++ b/build/gulpfile.extensions.js
@@ -3,6 +3,8 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
+/*global process,require,__dirname*/
+
 // Increase max listeners for event emitters
 require('events').EventEmitter.defaultMaxListeners = 100;
 
@@ -10,9 +12,7 @@ var gulp = require('gulp');
 var path = require('path');
 var tsb = require('gulp-tsb');
 var es = require('event-stream');
-var cp = require('child_process');
 var filter = require('gulp-filter');
-var rename = require('gulp-rename');
 var rimraf = require('rimraf');
 var util = require('./lib/util');
 var watcher = require('./lib/watch');
diff --git a/build/gulpfile.hygiene.js b/build/gulpfile.hygiene.js
index cfc61e0508a..b064276a58b 100644
--- a/build/gulpfile.hygiene.js
+++ b/build/gulpfile.hygiene.js
@@ -3,10 +3,11 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
+/*global process,require,console,exports,module*/
+
 var gulp = require('gulp');
 var filter = require('gulp-filter');
 var es = require('event-stream');
-var path = require('path');
 var gulptslint = require('gulp-tslint');
 var tslint = require('tslint');
 
@@ -161,7 +162,7 @@ var hygiene = exports.hygiene = function (some) {
 	});
 
 	var tsl = es.through(function(file) {
-		configuration = tslint.findConfiguration(null, '.');
+		var configuration = tslint.findConfiguration(null, '.');
 		var options = {
 			formatter: 'json',
 			configuration: configuration,