diff --git a/types/connect-mongo/index.d.ts b/types/connect-mongo/index.d.ts
index cf3d5ddb3e..ee110ab6b0 100644
--- a/types/connect-mongo/index.d.ts
+++ b/types/connect-mongo/index.d.ts
@@ -104,11 +104,11 @@ declare namespace connectMongo {
     }
 
     export class MongoStore extends session.Store {
-        get: (sid: string, callback: (err: any, session: Express.Session) => void) => void;
+        get: (sid: string, callback: (err: any, session: Express.Session | null) => void) => void;
         set: (sid: string, session: Express.Session, callback?: (err: any) => void) => void;
         destroy: (sid: string, callback?: (err: any) => void) => void;
         length: (callback: (err: any, length: number) => void) => void;
-        clear: (callback?: (err: any) => void) => void;
+        clear: (callback?: (err?: any) => void) => void;
         touch: (sid: string, session: Express.Session, callback?: (err: any) => void) => void;
     }
 }