diff --git a/deno.json b/deno.json
index 66ebc92..0753ab8 100644
--- a/deno.json
+++ b/deno.json
@@ -1,14 +1,18 @@
 {
   "name": "@oak/acorn",
-  "version": "0.5.1-alpha.2",
+  "version": "0.5.1-alpha.3",
   "exports": {
     ".": "./mod.ts",
     "./context": "./context.ts",
     "./handlers": "./handlers.ts",
+    "./http_server_bun": "./http_server_bun.ts",
     "./http_server_deno": "./http_server_deno.ts",
     "./router": "./router.ts",
     "./types": "./types.ts"
   },
+  "imports": {
+    "urlpattern-polyfill": "npm:urlpattern-polyfill@10.0.0"
+  },
   "tasks": {
     "bench": "deno bench",
     "example": "deno run --allow-net --allow-hrtime _examples/server.ts",
diff --git a/router.ts b/router.ts
index 35d65b1..f49809c 100644
--- a/router.ts
+++ b/router.ts
@@ -60,7 +60,7 @@ import {
 } from "./util.ts";
 
 if (!("URLPattern" in globalThis)) {
-  await import("npm:urlpattern-polyfill");
+  await import("urlpattern-polyfill");
 }
 
 /** Valid return values from a route handler. */