diff --git a/mod.ts b/mod.ts
index d2a7250..fa28cd6 100644
--- a/mod.ts
+++ b/mod.ts
@@ -1,5 +1,10 @@
 import { assertEquals, assertMatch, parseMediaType } from './deps.ts'
-import { Handler, HandlerOrListener } from './types.ts'
+import type {
+  FetchFunction,
+  Handler,
+  HandlerOrListener,
+  MakeFetchResponse,
+} from './types.ts'
 
 // credit - 'https://deno.land/x/free_port@v1.2.0/mod.ts'
 function random(min: number, max: number): number {
@@ -22,15 +27,6 @@ const getFreeListener = (
   throw new Error('Unable to get free port')
 }
 
-type Expect = {
-  expectStatus: (a: number, b?: string) => Expect
-  expectHeader: (a: string, b: string | RegExp | null | string[]) => Expect
-  expectBody: (a: unknown) => void
-  expect: (a: unknown, b?: unknown) => Expect
-}
-
-type MakeFetchResponse = { port: number } & Response & Expect
-
 const fetchEndpoint = async (
   port: number,
   url: string | URL,
@@ -97,7 +93,7 @@ const makeFetchPromise = (handlerOrListener: HandlerOrListener) => {
   }
 }
 
-export const makeFetch = (h: HandlerOrListener) => {
+export const makeFetch = (h: HandlerOrListener): FetchFunction => {
   const { resp, port } = makeFetchPromise(h)
   async function fetch(url: string | URL, options?: RequestInit) {
     const { res, data } = await resp(url, options)
diff --git a/types.ts b/types.ts
index d067f07..a792f09 100644
--- a/types.ts
+++ b/types.ts
@@ -4,3 +4,17 @@ export type Handler = (
 ) => Response | Promise<Response>
 
 export type HandlerOrListener = Handler | Deno.Listener
+
+export type MakeFetchResponse = { port: number } & Response & Expect
+
+export type FetchFunction = (
+  url: string | URL,
+  options?: RequestInit,
+) => Promise<MakeFetchResponse>
+
+export type Expect = {
+  expectStatus: (a: number, b?: string) => Expect
+  expectHeader: (a: string, b: string | RegExp | null | string[]) => Expect
+  expectBody: (a: unknown) => void
+  expect: (a: unknown, b?: unknown) => Expect
+}