diff --git a/types/express-session/index.d.ts b/types/express-session/index.d.ts
index 13ce6ab8b2..20343873f1 100644
--- a/types/express-session/index.d.ts
+++ b/types/express-session/index.d.ts
@@ -1,6 +1,8 @@
 // Type definitions for express-session 1.15
 // Project: https://www.npmjs.org/package/express-session
-// Definitions by: Hiroki Horiuchi <https://github.com/horiuchi>, Jacob Bogers <https://github.com/jacobbogers>
+// Definitions by: Hiroki Horiuchi <https://github.com/horiuchi>
+//                 Jacob Bogers <https://github.com/jacobbogers>
+//                 Ryan Cannon <https://github.com/ry7n>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.2
 
@@ -51,7 +53,7 @@ declare function session(options?: session.SessionOptions): express.RequestHandl
 
 declare namespace session {
   interface SessionOptions {
-    secret: string;
+    secret: string | string[];
     name?: string;
     store?: Store | MemoryStore;
     cookie?: express.CookieOptions;