diff --git a/deno.json b/deno.json
index ec46284..78beae6 100644
--- a/deno.json
+++ b/deno.json
@@ -1,6 +1,6 @@
 {
   "name": "@oak/acorn",
-  "version": "0.5.1-alpha.4",
+  "version": "0.5.1-alpha.5",
   "exports": {
     ".": "./mod.ts",
     "./context": "./context.ts",
diff --git a/package.json b/package.json
deleted file mode 100644
index 2a7bf42..0000000
--- a/package.json
+++ /dev/null
@@ -1,5 +0,0 @@
-{
-  "dependencies": {
-    "urlpattern-polyfill": "npm:urlpattern-polyfill@10.0.0"
-  }
-}
diff --git a/router.ts b/router.ts
index f49809c..16ef4e4 100644
--- a/router.ts
+++ b/router.ts
@@ -60,7 +60,7 @@ import {
 } from "./util.ts";
 
 if (!("URLPattern" in globalThis)) {
-  await import("urlpattern-polyfill");
+  await import("npm:urlpattern-polyfill@10.0.0");
 }
 
 /** Valid return values from a route handler. */