diff --git a/types/express-serve-static-core/index.d.ts b/types/express-serve-static-core/index.d.ts
index dd012cab4e..e9c136e7ea 100644
--- a/types/express-serve-static-core/index.d.ts
+++ b/types/express-serve-static-core/index.d.ts
@@ -197,11 +197,11 @@ interface Request extends http.IncomingMessage, Express.Request {
         *
         * @param name
         */
-    get(name: string): string;
+    get(name: string): string | undefined;
 
-    header(name: string): string;
+    header(name: string): string | undefined;
 
-    headers: { [key: string]: string; };
+    headers: { [key: string]: string | undefined; };
 
     /**
         * Check if the given `type(s)` is acceptable, returning
diff --git a/types/express-serve-static-core/tsconfig.json b/types/express-serve-static-core/tsconfig.json
index 40ee779963..cdb77c3573 100644
--- a/types/express-serve-static-core/tsconfig.json
+++ b/types/express-serve-static-core/tsconfig.json
@@ -6,7 +6,7 @@
         ],
         "noImplicitAny": true,
         "noImplicitThis": true,
-        "strictNullChecks": false,
+        "strictNullChecks": true,
         "baseUrl": "../",
         "typeRoots": [
             "../"
diff --git a/types/express/express-tests.ts b/types/express/express-tests.ts
index 04165d5e09..cc8c63ef81 100644
--- a/types/express/express-tests.ts
+++ b/types/express/express-tests.ts
@@ -71,6 +71,15 @@ namespace express_tests {
         language = req.acceptsLanguages(['en', 'ja']);
         language = req.acceptsLanguages('en', 'ja');
 
+        let existingHeader1 = req.get('existingHeader') as string;
+        let nonExistingHeader1 = req.get('nonExistingHeader') as undefined;
+
+        let existingHeader2 = req.header('existingHeader') as string;
+        let nonExistingHeader2 = req.header('nonExistingHeader') as undefined;
+
+        let existingHeader3 = req.headers.existingHeader as string;
+        let nonExistingHeader3 = req.headers.nonExistingHeader as undefined;
+
         res.send(req.query['token']);
     });
 
diff --git a/types/express/index.d.ts b/types/express/index.d.ts
index 9b913db473..d48d58c0c9 100644
--- a/types/express/index.d.ts
+++ b/types/express/index.d.ts
@@ -2,6 +2,7 @@
 // Project: http://expressjs.com
 // Definitions by: Boris Yankov <https://github.com/borisyankov/>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.2
 
 /* =================== USAGE ===================
 
diff --git a/types/express/tsconfig.json b/types/express/tsconfig.json
index 0fc87c2800..009cb9ec00 100644
--- a/types/express/tsconfig.json
+++ b/types/express/tsconfig.json
@@ -6,7 +6,7 @@
         ],
         "noImplicitAny": true,
         "noImplicitThis": true,
-        "strictNullChecks": false,
+        "strictNullChecks": true,
         "baseUrl": "../",
         "typeRoots": [
             "../"