diff --git a/types/request-ip/index.d.ts b/types/request-ip/index.d.ts
index e86ca3fe90..9658b198e3 100644
--- a/types/request-ip/index.d.ts
+++ b/types/request-ip/index.d.ts
@@ -38,7 +38,7 @@ interface Options {
     attributeName: string;
 }
 
-export declare function getClientIp(req: Request): string;
+export declare function getClientIp(req: Request): string | null;
 
 export function mw(options?: Options): (req: Request, res: any, next: any) => any;