diff --git a/locales/en.yml b/locales/en.yml
index 4dadcb806..8392e170c 100644
--- a/locales/en.yml
+++ b/locales/en.yml
@@ -311,6 +311,9 @@ desktop:
       url: "https://www.google.com/landing/2step/"
       caution: "As a caveat, security improves, but you can not sign in to Misskey if you lose a registered device, etc."
       register: "Register a device"
+      already-registered: "The setting has already been completed."
+      unregister: "Disable"
+      unregistered: "Two-step authentication has been disabled."
       enter-password: "Enter the password"
       authenticator: "First, you need install Google Authenticator to your device:"
       howtoinstall: "How to install"
diff --git a/locales/ja.yml b/locales/ja.yml
index d38ae682e..f9d41d909 100644
--- a/locales/ja.yml
+++ b/locales/ja.yml
@@ -311,6 +311,9 @@ desktop:
       url: "https://www.google.co.jp/intl/ja/landing/2step/"
       caution: "登録したデバイスを紛失するなどした場合、Misskeyにサインインできなくなりますのでご注意ください。"
       register: "デバイスを登録する"
+      already-registered: "既に設定は完了しています。"
+      unregister: "設定を解除"
+      unregistered: "二段階認証が無効になりました。"
       enter-password: "パスワードを入力してください"
       authenticator: "まず、Google Authenticatorをお使いのデバイスにインストールします:"
       howtoinstall: "インストール方法はこちら"
diff --git a/src/api/endpoints.ts b/src/api/endpoints.ts
index 49871c0ce..1138df193 100644
--- a/src/api/endpoints.ts
+++ b/src/api/endpoints.ts
@@ -157,11 +157,18 @@ const endpoints: Endpoint[] = [
 	},
 	{
 		name: 'i/2fa/register',
-		withCredential: true
+		withCredential: true,
+		secure: true
+	},
+	{
+		name: 'i/2fa/unregister',
+		withCredential: true,
+		secure: true
 	},
 	{
 		name: 'i/2fa/done',
-		withCredential: true
+		withCredential: true,
+		secure: true
 	},
 	{
 		name: 'i/update',
@@ -179,11 +186,13 @@ const endpoints: Endpoint[] = [
 	},
 	{
 		name: 'i/change_password',
-		withCredential: true
+		withCredential: true,
+		secure: true
 	},
 	{
 		name: 'i/regenerate_token',
-		withCredential: true
+		withCredential: true,
+		secure: true
 	},
 	{
 		name: 'i/pin',
diff --git a/src/api/endpoints/i/2fa/unregister.ts b/src/api/endpoints/i/2fa/unregister.ts
new file mode 100644
index 000000000..6bee6a26f
--- /dev/null
+++ b/src/api/endpoints/i/2fa/unregister.ts
@@ -0,0 +1,28 @@
+/**
+ * Module dependencies
+ */
+import $ from 'cafy';
+import * as bcrypt from 'bcryptjs';
+import User from '../../../models/user';
+
+module.exports = async (params, user) => new Promise(async (res, rej) => {
+	// Get 'password' parameter
+	const [password, passwordErr] = $(params.password).string().$;
+	if (passwordErr) return rej('invalid password param');
+
+	// Compare password
+	const same = await bcrypt.compare(password, user.password);
+
+	if (!same) {
+		return rej('incorrect password');
+	}
+
+	await User.update(user._id, {
+		$set: {
+			two_factor_secret: null,
+			two_factor_enabled: false
+		}
+	});
+
+	res();
+});
diff --git a/src/web/app/desktop/tags/settings.tag b/src/web/app/desktop/tags/settings.tag
index 9f71da687..3fa1f50fc 100644
--- a/src/web/app/desktop/tags/settings.tag
+++ b/src/web/app/desktop/tags/settings.tag
@@ -266,7 +266,11 @@
 <mk-2fa-setting>
 	<p>%i18n:desktop.tags.mk-2fa-setting.intro%<a href="%i18n:desktop.tags.mk-2fa-setting.url%" target="_blank">%i18n:desktop.tags.mk-2fa-setting.detail%</a></p>
 	<div class="ui info warn"><p>%fa:exclamation-triangle%%i18n:desktop.tags.mk-2fa-setting.caution%</p></div>
-	<p if={ !data }><button onclick={ register } class="ui primary">%i18n:desktop.tags.mk-2fa-setting.register%</button></p>
+	<p if={ !data && !I.two_factor_enabled }><button onclick={ register } class="ui primary">%i18n:desktop.tags.mk-2fa-setting.register%</button></p>
+	<virtual if={ I.two_factor_enabled }>
+		<p>%i18n:desktop.tags.mk-2fa-setting.already-registered%</p>
+		<button onclick={ unregister } class="ui">%i18n:desktop.tags.mk-2fa-setting.unregister%</button>
+	</virtual>
 	<div if={ data }>
 		<ol>
 			<li>%i18n:desktop.tags.mk-2fa-setting.authenticator% <a href="https://support.google.com/accounts/answer/1066447" target="_blank">%i18n:desktop.tags.mk-2fa-setting.howtoinstall%</a></li>
@@ -288,6 +292,7 @@
 		import passwordDialog from '../scripts/password-dialog';
 		import notify from '../scripts/notify';
 
+		this.mixin('i');
 		this.mixin('api');
 
 		this.register = () => {
@@ -302,11 +307,25 @@
 			});
 		};
 
+		this.unregister = () => {
+			passwordDialog('%i18n:desktop.tags.mk-2fa-setting.enter-password%', password => {
+				this.api('i/2fa/unregister', {
+					password: password
+				}).then(data => {
+					notify('%i18n:desktop.tags.mk-2fa-setting.unregistered%');
+					this.I.two_factor_enabled = false;
+					this.I.update();
+				});
+			});
+		};
+
 		this.submit = () => {
 			this.api('i/2fa/done', {
 				token: this.refs.token.value
 			}).then(() => {
 				notify('%i18n:desktop.tags.mk-2fa-setting.success%');
+				this.I.two_factor_enabled = true;
+				this.I.update();
 			}).catch(() => {
 				notify('%i18n:desktop.tags.mk-2fa-setting.failed%');
 			});