diff --git a/build.ts b/build.ts
index 16b75655..ddc64dfb 100644
--- a/build.ts
+++ b/build.ts
@@ -1,12 +1,15 @@
 import { existsSync } from "https://deno.land/std/fs/exists.ts";
-import { resolve } from "https://deno.land/std/path/mod.ts";
+import { resolve, extname } from "https://deno.land/std/path/mod.ts";
 
 export async function copyTargets() {
   await Deno.mkdir(".deno_plugins", { recursive: true });
   const targets = ["libdeno_mongo.dylib", "libdeno_mongo.so", "deno_mongo.dll"];
   for (const target of targets) {
     const targetPath = resolve("./target/release", target);
-    const targetToPath = resolve(".deno_plugins", target);
+    const targetToPath = resolve(
+      ".deno_plugins",
+      `deno_mongo${extname(target)}`
+    );
     if (existsSync(targetPath)) {
       console.log(`Copy "${targetPath}" to "${targetToPath}"`);
       await Deno.copyFile(targetPath, targetToPath);
diff --git a/test.ts b/test.ts
index b4dcd36d..cd81ae7d 100644
--- a/test.ts
+++ b/test.ts
@@ -74,5 +74,5 @@ test(async function testDeleteOne() {
 });
 
 await cargoBuild();
-await init();
+await init("master");
 await runTests();
diff --git a/ts/util.ts b/ts/util.ts
index f09c3fdc..39648f9e 100644
--- a/ts/util.ts
+++ b/ts/util.ts
@@ -17,9 +17,8 @@ interface Command {
   command_id?: number;
 }
 
-export async function init() {
-  let releaseUrl =
-    "https://github.com/manyuanrong/deno_mongo/releases/download/master";
+export async function init(binVer: string = "master") {
+  let releaseUrl = `https://github.com/manyuanrong/deno_mongo/releases/download/${binVer}`;
 
   const options = {
     name: PLUGIN_NAME,