diff --git a/types/express-http-proxy/express-http-proxy-tests.ts b/types/express-http-proxy/express-http-proxy-tests.ts
index 56156369cc..c96ec0fc8d 100644
--- a/types/express-http-proxy/express-http-proxy-tests.ts
+++ b/types/express-http-proxy/express-http-proxy-tests.ts
@@ -26,3 +26,5 @@ proxy('www.google.com', {
         return headers;
     }
 });
+
+proxy((req) => 'com.google.www'.split('.').reverse().join('.'));
diff --git a/types/express-http-proxy/index.d.ts b/types/express-http-proxy/index.d.ts
index 3a74bef6db..d1935f3bc3 100644
--- a/types/express-http-proxy/index.d.ts
+++ b/types/express-http-proxy/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/villadora/express-http-proxy#readme
 // Definitions by:  ulrichb <https://github.com/ulrichb>
 //                  Daniel Schopf <https://github.com/Danscho>
+//                  Gabriel Fournier <https://github.com/carboneater>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.2
 
@@ -15,6 +16,6 @@ interface ProxyOptions {
     userResHeaderDecorator?: (headers: IncomingHttpHeaders, userReq: Request, userRes: Response, proxyReq: Request, proxyRes: Response) => OutgoingHttpHeaders;
 }
 
-declare function proxy(host: string, options?: ProxyOptions): RequestHandler;
+declare function proxy(host: string|((req: Request) => string), options?: ProxyOptions): RequestHandler;
 
 export = proxy;