diff --git a/express-serve-static-core/express-serve-static-core.d.ts b/express-serve-static-core/express-serve-static-core.d.ts
index f83e509e63..745b0e6ab2 100644
--- a/express-serve-static-core/express-serve-static-core.d.ts
+++ b/express-serve-static-core/express-serve-static-core.d.ts
@@ -117,7 +117,7 @@ declare module "express-serve-static-core" {
     interface CookieOptions {
         maxAge?: number;
         signed?: boolean;
-        expires?: Date;
+        expires?: Date | boolean;
         httpOnly?: boolean;
         path?: string;
         domain?: string;
diff --git a/express-session/express-session.d.ts b/express-session/express-session.d.ts
index 156e9404fc..90e1ed07cc 100644
--- a/express-session/express-session.d.ts
+++ b/express-session/express-session.d.ts
@@ -30,7 +30,7 @@ declare namespace Express {
     secure?: boolean;
     httpOnly: boolean;
     domain?: string;
-    expires: Date;
+    expires: Date | boolean;
     serialize: (name: string, value: string) => string;
   }
 }