diff --git a/src/command/close.rs b/src/command/close.rs
new file mode 100644
index 00000000..d8fd6a8d
--- /dev/null
+++ b/src/command/close.rs
@@ -0,0 +1,13 @@
+use crate::*;
+
+#[derive(Serialize, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct CloseResult {
+    success: bool,
+}
+
+pub fn close(command: Command) -> util::JsonResult<CloseResult> {
+    let client_id: &usize = &command.args.client_id.unwrap();
+    CLIENTS.lock().map_err(|e| e.to_string())?.remove(client_id);
+    Ok(CloseResult { success: true })
+}
diff --git a/src/command/mod.rs b/src/command/mod.rs
index c77d7a14..67debf6b 100644
--- a/src/command/mod.rs
+++ b/src/command/mod.rs
@@ -1,4 +1,5 @@
 mod aggregation;
+mod close;
 mod connect;
 mod count;
 mod delete;
@@ -11,6 +12,7 @@ mod list_database_names;
 mod update;
 
 pub use aggregation::aggregate;
+pub use close::close;
 pub use connect::{connect_with_options, connect_with_uri};
 pub use count::count;
 pub use delete::delete;
diff --git a/src/lib.rs b/src/lib.rs
index a6b28237..fb043058 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -35,6 +35,7 @@ lazy_static! {
 pub enum CommandType {
     ConnectWithOptions,
     ConnectWithUri,
+    Close,
     ListDatabases,
     Find,
     ListCollectionNames,
@@ -114,6 +115,7 @@ fn op_command(_interface: &mut dyn Interface, zero_copy: &mut [ZeroCopyBuf]) ->
     match args2.command_type {
         CommandType::ConnectWithOptions => util::sync_op(command::connect_with_options, command),
         CommandType::ConnectWithUri => util::sync_op(command::connect_with_uri, command),
+        CommandType::Close => util::sync_op(command::close, command),
         CommandType::ListDatabases => util::async_op(command::list_database_names, command),
         CommandType::ListCollectionNames => util::async_op(command::list_collection_names, command),
         CommandType::Find => util::async_op(command::find, command),
diff --git a/test.ts b/test.ts
index 380d179d..30a4c827 100644
--- a/test.ts
+++ b/test.ts
@@ -1,13 +1,13 @@
 import { cargoBuild } from "./build.ts";
-import { init } from "./ts/util.ts";
-import { MongoClient } from "./ts/client.ts";
 import {
   assert,
   assertEquals,
-  exists,
   assertThrowsAsync,
+  exists,
 } from "./test.deps.ts";
+import { MongoClient } from "./ts/client.ts";
 import { ObjectId } from "./ts/types.ts";
+import { init } from "./ts/util.ts";
 interface IUser {
   username: string;
   password: string;
@@ -17,9 +17,13 @@ interface IUser {
 const { test } = Deno;
 const dateNow = Date.now();
 
+let testClient: MongoClient | undefined;
+
 function getClient(): MongoClient {
+  if (testClient) return testClient;
   const client = new MongoClient();
   client.connectWithUri("mongodb://localhost:27017");
+  testClient = client;
   return client;
 }
 
@@ -73,13 +77,17 @@ test("testInsertOne", async () => {
 test("testUpsertOne", async () => {
   const db = getClient().database("test");
   const users = db.collection<IUser>("mongo_test_users");
-  const { upsertedId } = await users.updateOne({
-    _id: ObjectId("aaaaaaaaaaaaaaaaaaaaaaaa"),
-  }, {
-    username: "user1",
-    password: "pass1",
-    date: new Date(dateNow),
-  }, { upsert: true });
+  const { upsertedId } = await users.updateOne(
+    {
+      _id: ObjectId("aaaaaaaaaaaaaaaaaaaaaaaa"),
+    },
+    {
+      username: "user1",
+      password: "pass1",
+      date: new Date(dateNow),
+    },
+    { upsert: true }
+  );
 
   assert(upsertedId);
   assertEquals(Object.keys(upsertedId), ["$oid"]);
@@ -111,7 +119,7 @@ test("testInsertOneTwice", async () => {
         username: "user1",
       }) as any,
     undefined,
-    "E11000",
+    "E11000"
   );
 });
 
@@ -162,11 +170,14 @@ test("testFindOr", async () => {
   const db = getClient().database("test");
   const users = db.collection<IUser>("mongo_test_users");
   const user1 = await users.find({
-    $or: [{
-      password: "pass1",
-    }, {
-      password: "pass2",
-    }],
+    $or: [
+      {
+        password: "pass1",
+      },
+      {
+        password: "pass2",
+      },
+    ],
   });
 
   assert(user1 instanceof Array);
@@ -178,7 +189,7 @@ test("testFind", async () => {
   const users = db.collection("mongo_test_users");
   const findUsers = await users.find(
     { username: "many" },
-    { skip: 1, limit: 1 },
+    { skip: 1, limit: 1 }
   );
   assert(findUsers instanceof Array);
   assertEquals(findUsers.length, 1);
@@ -209,7 +220,7 @@ test("testUpdateMany", async () => {
   const users = db.collection("mongo_test_users");
   const result = await users.updateMany(
     { username: "many" },
-    { $set: { username: "MANY" } },
+    { $set: { username: "MANY" } }
   );
   assertEquals(result, { matchedCount: 2, modifiedCount: 2, upsertedId: null });
 });
@@ -238,6 +249,12 @@ test("testDistinct", async () => {
 //   console.log(result);
 // });
 
+test("testClose", async () => {
+  const result = getClient().close();
+  assertEquals(result, { success: true });
+  testClient = undefined;
+});
+
 if (await exists(".deno_plugins")) {
   await Deno.remove(".deno_plugins", { recursive: true });
 }
diff --git a/ts/client.ts b/ts/client.ts
index 56c21242..263efbab 100644
--- a/ts/client.ts
+++ b/ts/client.ts
@@ -1,6 +1,6 @@
 import { Database } from "./database.ts";
 import { CommandType } from "./types.ts";
-import { decode, dispatch, dispatchAsync, encode } from "./util.ts";
+import { dispatch, dispatchAsync, encode } from "./util.ts";
 
 export interface ClientOptions {
   /**
@@ -100,7 +100,7 @@ export class MongoClient {
   connectWithUri(uri: string) {
     const data = dispatch(
       { command_type: CommandType.ConnectWithUri },
-      encode(uri),
+      encode(uri)
     ) as ConnectResult;
     this._clientId = data.clientId;
   }
@@ -108,7 +108,7 @@ export class MongoClient {
   connectWithOptions(options: ClientOptions) {
     const data = dispatch(
       { command_type: CommandType.ConnectWithOptions },
-      encode(JSON.stringify(options)),
+      encode(JSON.stringify(options))
     ) as ConnectResult;
     this._clientId = data.clientId;
   }
@@ -120,6 +120,15 @@ export class MongoClient {
     })) as string[];
   }
 
+  close() {
+    return dispatch({
+      command_type: CommandType.Close,
+      client_id: this._clientId,
+    }) as {
+      success: boolean;
+    };
+  }
+
   database(name: string): Database {
     return new Database(this, name);
   }
diff --git a/ts/types.ts b/ts/types.ts
index 2afde110..9134d789 100644
--- a/ts/types.ts
+++ b/ts/types.ts
@@ -1,6 +1,7 @@
 export enum CommandType {
   ConnectWithUri = "ConnectWithUri",
   ConnectWithOptions = "ConnectWithOptions",
+  Close = "Close",
   ListDatabases = "ListDatabases",
   ListCollectionNames = "ListCollectionNames",
   Find = "Find",