diff --git a/download.ts b/download.ts
index 9e7a660..7514f20 100644
--- a/download.ts
+++ b/download.ts
@@ -7,7 +7,6 @@ import {
   join,
   normalize,
   resolve,
-  toFileUrl,
 } from "./deps.ts";
 import {
   ArchRecord,
@@ -16,7 +15,13 @@ import {
   NestedCrossRecord,
   OsRecord,
 } from "./types.ts";
-import { cacheDir, denoCacheDir, isFile, urlToFilename } from "./util.ts";
+import {
+  cacheDir,
+  denoCacheDir,
+  isFile,
+  stringToURL,
+  urlToFilename,
+} from "./util.ts";
 
 export const defaultExtensions: OsRecord<string> = {
   darwin: "dylib",
@@ -99,9 +104,7 @@ export function createDownloadURL(options: FetchOptions): URL {
   if (options.url instanceof URL) {
     url = options.url;
   } else if (typeof options.url === "string") {
-    url = options.url.startsWith("file://")
-      ? new URL(options.url)
-      : toFileUrl(resolve(options.url));
+    url = stringToURL(options.url);
   } else {
     const tmpUrl = getCrossOption(options.url);
     if (tmpUrl === undefined) {
@@ -111,9 +114,7 @@ export function createDownloadURL(options: FetchOptions): URL {
     }
 
     if (typeof tmpUrl === "string") {
-      url = tmpUrl.startsWith("file://")
-        ? new URL(tmpUrl)
-        : toFileUrl(resolve(tmpUrl));
+      url = stringToURL(tmpUrl);
     } else {
       url = tmpUrl;
     }
@@ -244,10 +245,10 @@ export async function download(options: FetchOptions): Promise<string> {
           }
         }
 
-        const file = await Deno.create(cacheFilePath);
-        await response.body!.pipeTo(file.writable);
-        file.close();
-
+        await Deno.writeFile(
+          cacheFilePath,
+          new Uint8Array(await response.arrayBuffer()),
+        );
         break;
       }
 
diff --git a/download_test.ts b/download_test.ts
index 18d6bef..5439f2a 100644
--- a/download_test.ts
+++ b/download_test.ts
@@ -22,23 +22,63 @@ async function isDirectory(filePath: string): Promise<boolean> {
 }
 
 Deno.test("createDownloadURL", async ({ step }) => {
-  await step("string", () => {
-    const path = "./test/example";
-    const result = createDownloadURL(path);
-    assert(result.pathname.endsWith("/test/example"));
+  await step("string", async ({ step }) => {
+    await step("relative", () => {
+      const path = "./test/example";
+      const result = createDownloadURL(path);
+      assertEquals(
+        result.toString(),
+        new URL("./test/example", import.meta.url).toString(),
+      );
+    });
+
+    await step("file", () => {
+      const path = "file:///test/example";
+      const result = createDownloadURL(path);
+      assertEquals(result.toString(), "file:///test/example");
+    });
+
+    await step("http", () => {
+      const path = "http://example.com/example";
+      const result = createDownloadURL(path);
+      assertEquals(result.toString(), "http://example.com/example");
+    });
+
+    await step("https", () => {
+      const path = "https://example.com/example";
+      const result = createDownloadURL(path);
+      assertEquals(result.toString(), "https://example.com/example");
+    });
   });
 
-  await step("URL", () => {
-    const path = new URL("file://./test/example");
-    const result = createDownloadURL(path);
-    assertEquals(result, path);
+  await step("URL", async ({ step }) => {
+    await step("file", () => {
+      const path = new URL("file:///test/example");
+      const result = createDownloadURL(path);
+      assertEquals(result.toString(), "file:///test/example");
+    });
+
+    await step("http", () => {
+      const path = new URL("http://example.com/example");
+      const result = createDownloadURL(path);
+      assertEquals(result.toString(), "http://example.com/example");
+    });
+
+    await step("https", () => {
+      const path = new URL("https://example.com/example");
+      const result = createDownloadURL(path);
+      assertEquals(result.toString(), "https://example.com/example");
+    });
   });
 
   await step("URLOptions", async ({ step }) => {
     await step("string", () => {
       const path = "./test/example";
       const result = createDownloadURL({ url: path });
-      assert(result.pathname.endsWith("/test/example"));
+      assertEquals(
+        result.toString(),
+        new URL("./test/example", import.meta.url).toString(),
+      );
     });
 
     await step("URL", () => {
diff --git a/util.ts b/util.ts
index 659814f..cca5b5f 100644
--- a/util.ts
+++ b/util.ts
@@ -1,4 +1,11 @@
-import { hex, isAbsolute, join, normalize } from "./deps.ts";
+import {
+  hex,
+  isAbsolute,
+  join,
+  normalize,
+  resolve,
+  toFileUrl,
+} from "./deps.ts";
 
 export const encoder = new TextEncoder();
 export const decoder = new TextDecoder();
@@ -29,6 +36,15 @@ function baseUrlToFilename(url: URL): string {
   return join(...out);
 }
 
+export function stringToURL(url: string): URL {
+  // deno-fmt-ignore
+  return url.startsWith("file://")
+      || url.startsWith("http://")
+      || url.startsWith("https://")
+    ? new URL(url)
+    : toFileUrl(resolve(url));
+}
+
 export async function hash(value: string): Promise<string> {
   return decoder.decode(
     hex(
diff --git a/util_test.ts b/util_test.ts
index 1e7a4a9..21e9341 100644
--- a/util_test.ts
+++ b/util_test.ts
@@ -15,6 +15,7 @@ import {
   hash,
   homeDir,
   isFile,
+  stringToURL,
   urlToFilename,
 } from "./util.ts";
 
@@ -25,6 +26,35 @@ Deno.test("hash", async () => {
   );
 });
 
+Deno.test("stringToURL", async ({ step }) => {
+  await step("relative", () => {
+    const path = "./test/example";
+    const result = stringToURL(path);
+    assertEquals(
+      result.toString(),
+      new URL("./test/example", import.meta.url).toString(),
+    );
+  });
+
+  await step("file", () => {
+    const path = "file:///test/example";
+    const result = stringToURL(path);
+    assertEquals(result.toString(), "file:///test/example");
+  });
+
+  await step("http", () => {
+    const path = "http://example.com/example";
+    const result = stringToURL(path);
+    assertEquals(result.toString(), "http://example.com/example");
+  });
+
+  await step("https", () => {
+    const path = "https://example.com/example";
+    const result = stringToURL(path);
+    assertEquals(result.toString(), "https://example.com/example");
+  });
+});
+
 Deno.test("urlToFilename", async ({ step }) => {
   await step("http", async () => {
     assertEquals(