diff --git a/examples/auth/index.js b/examples/auth/index.js
index 70110891..36205d0f 100644
--- a/examples/auth/index.js
+++ b/examples/auth/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/content-negotiation/db.js b/examples/content-negotiation/db.js
index 43fb04ba..f59b23bf 100644
--- a/examples/content-negotiation/db.js
+++ b/examples/content-negotiation/db.js
@@ -1,3 +1,5 @@
+'use strict'
+
 var users = [];
 
 users.push({ name: 'Tobi' });
diff --git a/examples/content-negotiation/index.js b/examples/content-negotiation/index.js
index 348929e8..280a4e22 100644
--- a/examples/content-negotiation/index.js
+++ b/examples/content-negotiation/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 var express = require('../../');
 var app = module.exports = express();
 var users = require('./db');
diff --git a/examples/content-negotiation/users.js b/examples/content-negotiation/users.js
index fe511072..fe703e73 100644
--- a/examples/content-negotiation/users.js
+++ b/examples/content-negotiation/users.js
@@ -1,3 +1,4 @@
+'use strict'
 
 var users = require('./db');
 
diff --git a/examples/cookie-sessions/index.js b/examples/cookie-sessions/index.js
index 1dda15de..01c731c1 100644
--- a/examples/cookie-sessions/index.js
+++ b/examples/cookie-sessions/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/cookies/index.js b/examples/cookies/index.js
index 93515e59..04093591 100644
--- a/examples/cookies/index.js
+++ b/examples/cookies/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/downloads/index.js b/examples/downloads/index.js
index 9321f3bf..91c52bb8 100644
--- a/examples/downloads/index.js
+++ b/examples/downloads/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/ejs/index.js b/examples/ejs/index.js
index 72780912..a39d805a 100644
--- a/examples/ejs/index.js
+++ b/examples/ejs/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/error-pages/index.js b/examples/error-pages/index.js
index 44333cb0..efa815c4 100644
--- a/examples/error-pages/index.js
+++ b/examples/error-pages/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/error/index.js b/examples/error/index.js
index 07814d85..d922de06 100644
--- a/examples/error/index.js
+++ b/examples/error/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/hello-world/index.js b/examples/hello-world/index.js
index d82452f3..8c1855c2 100644
--- a/examples/hello-world/index.js
+++ b/examples/hello-world/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 var express = require('../../');
 
 var app = module.exports = express()
diff --git a/examples/markdown/index.js b/examples/markdown/index.js
index df8c195f..74ac05e7 100644
--- a/examples/markdown/index.js
+++ b/examples/markdown/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/multi-router/controllers/api_v1.js b/examples/multi-router/controllers/api_v1.js
index 08b7b5e6..a301e3ee 100644
--- a/examples/multi-router/controllers/api_v1.js
+++ b/examples/multi-router/controllers/api_v1.js
@@ -1,3 +1,5 @@
+'use strict'
+
 var express = require('../../..');
 
 var apiv1 = express.Router();
diff --git a/examples/multi-router/controllers/api_v2.js b/examples/multi-router/controllers/api_v2.js
index 4dd70828..e997fb1f 100644
--- a/examples/multi-router/controllers/api_v2.js
+++ b/examples/multi-router/controllers/api_v2.js
@@ -1,3 +1,5 @@
+'use strict'
+
 var express = require('../../..');
 
 var apiv2 = express.Router();
diff --git a/examples/multi-router/index.js b/examples/multi-router/index.js
index 78bae9d6..dbfd2841 100644
--- a/examples/multi-router/index.js
+++ b/examples/multi-router/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 var express = require('../..');
 
 var app = module.exports = express();
diff --git a/examples/multipart/index.js b/examples/multipart/index.js
index 42c2af23..ea7b86e0 100644
--- a/examples/multipart/index.js
+++ b/examples/multipart/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/mvc/controllers/main/index.js b/examples/mvc/controllers/main/index.js
index 031862d3..74cde191 100644
--- a/examples/mvc/controllers/main/index.js
+++ b/examples/mvc/controllers/main/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 exports.index = function(req, res){
   res.redirect('/users');
 };
diff --git a/examples/mvc/controllers/pet/index.js b/examples/mvc/controllers/pet/index.js
index 157a98e8..214160f9 100644
--- a/examples/mvc/controllers/pet/index.js
+++ b/examples/mvc/controllers/pet/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/mvc/controllers/user-pet/index.js b/examples/mvc/controllers/user-pet/index.js
index 416b0074..42a29ade 100644
--- a/examples/mvc/controllers/user-pet/index.js
+++ b/examples/mvc/controllers/user-pet/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/mvc/controllers/user/index.js b/examples/mvc/controllers/user/index.js
index a7b0208c..ec3ae4c8 100644
--- a/examples/mvc/controllers/user/index.js
+++ b/examples/mvc/controllers/user/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/mvc/db.js b/examples/mvc/db.js
index c992afcf..94d1480f 100644
--- a/examples/mvc/db.js
+++ b/examples/mvc/db.js
@@ -1,3 +1,5 @@
+'use strict'
+
 // faux database
 
 var pets = exports.pets = [];
diff --git a/examples/mvc/index.js b/examples/mvc/index.js
index 77885a60..da4727b2 100644
--- a/examples/mvc/index.js
+++ b/examples/mvc/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/mvc/lib/boot.js b/examples/mvc/lib/boot.js
index 422330dc..0216e5d7 100644
--- a/examples/mvc/lib/boot.js
+++ b/examples/mvc/lib/boot.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/online/index.js b/examples/online/index.js
index f14474c0..0b5fdffc 100644
--- a/examples/online/index.js
+++ b/examples/online/index.js
@@ -1,3 +1,4 @@
+'use strict'
 
 // install redis first:
 // https://redis.io/
diff --git a/examples/params/index.js b/examples/params/index.js
index 5b57573d..b153b93b 100644
--- a/examples/params/index.js
+++ b/examples/params/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/resource/index.js b/examples/resource/index.js
index b79ad923..ff1f6fe1 100644
--- a/examples/resource/index.js
+++ b/examples/resource/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/route-map/index.js b/examples/route-map/index.js
index e7adf5fc..2bc28bd4 100644
--- a/examples/route-map/index.js
+++ b/examples/route-map/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/route-middleware/index.js b/examples/route-middleware/index.js
index e7a0901f..44ec13a9 100644
--- a/examples/route-middleware/index.js
+++ b/examples/route-middleware/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/route-separation/index.js b/examples/route-separation/index.js
index 65121091..5d483811 100644
--- a/examples/route-separation/index.js
+++ b/examples/route-separation/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/route-separation/post.js b/examples/route-separation/post.js
index e3f12e78..3a8e3a2d 100644
--- a/examples/route-separation/post.js
+++ b/examples/route-separation/post.js
@@ -1,3 +1,5 @@
+'use strict'
+
 // Fake posts database
 
 var posts = [
diff --git a/examples/route-separation/site.js b/examples/route-separation/site.js
index a3d20bc8..aee36d1b 100644
--- a/examples/route-separation/site.js
+++ b/examples/route-separation/site.js
@@ -1,3 +1,5 @@
+'use strict'
+
 exports.index = function(req, res){
   res.render('index', { title: 'Route Separation Example' });
 };
diff --git a/examples/route-separation/user.js b/examples/route-separation/user.js
index ef79b343..1c2aec7c 100644
--- a/examples/route-separation/user.js
+++ b/examples/route-separation/user.js
@@ -1,3 +1,5 @@
+'use strict'
+
 // Fake user database
 
 var users = [
diff --git a/examples/search/index.js b/examples/search/index.js
index 246993ca..0d19444e 100644
--- a/examples/search/index.js
+++ b/examples/search/index.js
@@ -1,3 +1,4 @@
+'use strict'
 
 // install redis first:
 // https://redis.io/
diff --git a/examples/search/public/client.js b/examples/search/public/client.js
index 75c37d8e..cd43faf7 100644
--- a/examples/search/public/client.js
+++ b/examples/search/public/client.js
@@ -1,3 +1,5 @@
+'use strict'
+
 var search = document.querySelector('[type=search]');
 var code = document.querySelector('pre');
 
diff --git a/examples/session/index.js b/examples/session/index.js
index 9bae48b8..2bb2b109 100644
--- a/examples/session/index.js
+++ b/examples/session/index.js
@@ -1,3 +1,4 @@
+'use strict'
 
 // install redis first:
 // https://redis.io/
diff --git a/examples/session/redis.js b/examples/session/redis.js
index 1338d6e9..bbbdc7fd 100644
--- a/examples/session/redis.js
+++ b/examples/session/redis.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/static-files/index.js b/examples/static-files/index.js
index 0e44313d..609c546b 100644
--- a/examples/static-files/index.js
+++ b/examples/static-files/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/vhost/index.js b/examples/vhost/index.js
index 4a0c17b8..a9499356 100644
--- a/examples/vhost/index.js
+++ b/examples/vhost/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/view-constructor/github-view.js b/examples/view-constructor/github-view.js
index 0a98a908..43d29336 100644
--- a/examples/view-constructor/github-view.js
+++ b/examples/view-constructor/github-view.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/view-constructor/index.js b/examples/view-constructor/index.js
index 175a254e..3d673670 100644
--- a/examples/view-constructor/index.js
+++ b/examples/view-constructor/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/view-locals/index.js b/examples/view-locals/index.js
index cb415096..bf52d2a8 100644
--- a/examples/view-locals/index.js
+++ b/examples/view-locals/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */
diff --git a/examples/view-locals/user.js b/examples/view-locals/user.js
index 90ab1f38..aaa6f85f 100644
--- a/examples/view-locals/user.js
+++ b/examples/view-locals/user.js
@@ -1,3 +1,5 @@
+'use strict'
+
 module.exports = User;
 
 // faux model
diff --git a/examples/web-service/index.js b/examples/web-service/index.js
index 3685619d..c22fea40 100644
--- a/examples/web-service/index.js
+++ b/examples/web-service/index.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /**
  * Module dependencies.
  */