diff --git a/Common/sources/commondefines.js b/Common/sources/commondefines.js
index 08931601..24e578f7 100644
--- a/Common/sources/commondefines.js
+++ b/Common/sources/commondefines.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var constants = require('./constants');
 
 function InputCommand(data) {
diff --git a/Common/sources/constants.js b/Common/sources/constants.js
index f96c8600..2938905d 100644
--- a/Common/sources/constants.js
+++ b/Common/sources/constants.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 exports.DOC_ID_PATTERN = '0-9-.a-zA-Z_=';
 exports.CHAR_DELIMITER = String.fromCharCode(5);
 exports.OUTPUT_NAME = 'output';
diff --git a/Common/sources/formatchecker.js b/Common/sources/formatchecker.js
index 6551ac75..ed6cda2c 100644
--- a/Common/sources/formatchecker.js
+++ b/Common/sources/formatchecker.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var path = require('path');
 var constants = require('./constants');
 var logger = require('./logger');
diff --git a/Common/sources/license.js b/Common/sources/license.js
index 1c4e05fe..cee86494 100644
--- a/Common/sources/license.js
+++ b/Common/sources/license.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 const crypto = require('crypto');
 const fs = require('fs');
 const config = require('config');
diff --git a/Common/sources/logger.js b/Common/sources/logger.js
index f91faabd..21e46147 100644
--- a/Common/sources/logger.js
+++ b/Common/sources/logger.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var config = require('config');
 
 var log4js = require('log4js');
diff --git a/Common/sources/statsdclient.js b/Common/sources/statsdclient.js
index 741bb156..49a802ff 100644
--- a/Common/sources/statsdclient.js
+++ b/Common/sources/statsdclient.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var statsD = require('node-statsd');
 var configStatsD = require('config').get('statsd');
 
diff --git a/Common/sources/storage-fs.js b/Common/sources/storage-fs.js
index c5e65ae4..8403c301 100644
--- a/Common/sources/storage-fs.js
+++ b/Common/sources/storage-fs.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var fs = require('fs');
 var path = require('path');
 var mkdirp = require('mkdirp');
diff --git a/DocService/sources/baseConnector.js b/DocService/sources/baseConnector.js
index 8cabbc11..39ec45d5 100644
--- a/DocService/sources/baseConnector.js
+++ b/DocService/sources/baseConnector.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var sqlDataBaseType = {
 	mySql		: 'mysql',
 	postgreSql	: 'postgres'
diff --git a/DocService/sources/converterservice.js b/DocService/sources/converterservice.js
index d1c93c68..7dc6ddfa 100644
--- a/DocService/sources/converterservice.js
+++ b/DocService/sources/converterservice.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var config = require('config');
 var co = require('co');
 var taskResult = require('./taskresult');
diff --git a/DocService/sources/database.js b/DocService/sources/database.js
index ce263203..5dcf9986 100644
--- a/DocService/sources/database.js
+++ b/DocService/sources/database.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var mongoDB = require('mongodb');
 var config = require('./config.json');
 var _errorConnection = true;
diff --git a/DocService/sources/fileuploaderservice.js b/DocService/sources/fileuploaderservice.js
index a006056b..b5c3080a 100644
--- a/DocService/sources/fileuploaderservice.js
+++ b/DocService/sources/fileuploaderservice.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var multiparty = require('multiparty');
 var co = require('co');
 var jwt = require('jsonwebtoken');
diff --git a/DocService/sources/fontservice.js b/DocService/sources/fontservice.js
index 02b287f2..78587db7 100644
--- a/DocService/sources/fontservice.js
+++ b/DocService/sources/fontservice.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var fs = require('fs');
 var path = require('path');
 var util = require('util');
diff --git a/DocService/sources/mySqlBaseConnector.js b/DocService/sources/mySqlBaseConnector.js
index 1db9b273..80313e1d 100644
--- a/DocService/sources/mySqlBaseConnector.js
+++ b/DocService/sources/mySqlBaseConnector.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var mysql = require('mysql');
 var sqlBase = require('./baseConnector');
 var configSql = require('config').get('services.CoAuthoring.sql');
diff --git a/DocService/sources/postgreSqlBaseConnector.js b/DocService/sources/postgreSqlBaseConnector.js
index efbd6f10..6afe4830 100644
--- a/DocService/sources/postgreSqlBaseConnector.js
+++ b/DocService/sources/postgreSqlBaseConnector.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var pg = require('pg');
 var co = require('co');
 var pgEscape = require('pg-escape');
diff --git a/DocService/sources/taskresult.js b/DocService/sources/taskresult.js
index 803a5e2c..21c16f7d 100644
--- a/DocService/sources/taskresult.js
+++ b/DocService/sources/taskresult.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var sqlBase = require('./baseConnector');
 var logger = require('./../../Common/sources/logger');
 var utils = require('./../../Common/sources/utils');
diff --git a/FileConverter/sources/convertermaster.js b/FileConverter/sources/convertermaster.js
index f6b7665e..f855cbbd 100644
--- a/FileConverter/sources/convertermaster.js
+++ b/FileConverter/sources/convertermaster.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 const cluster = require('cluster');
 const logger = require('./../../Common/sources/logger');
 
diff --git a/SpellChecker/sources/server.js b/SpellChecker/sources/server.js
index 93e244d9..be9e2f4e 100644
--- a/SpellChecker/sources/server.js
+++ b/SpellChecker/sources/server.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var cluster = require('cluster');
 var config = require('config').get('SpellChecker');
 
diff --git a/SpellChecker/sources/spellCheck.js b/SpellChecker/sources/spellCheck.js
index 59a2f348..4cc9629d 100644
--- a/SpellChecker/sources/spellCheck.js
+++ b/SpellChecker/sources/spellCheck.js
@@ -30,6 +30,8 @@
  *
  */
 
+'use strict';
+
 var sockjs = require('sockjs'),
 	nodehun = require('nodehun'),
     config = require('config').get('SpellChecker'),