diff --git a/lib/extend/tag.js b/lib/extend/tag.js
index 03f6a66626..31f9f2aa5b 100644
--- a/lib/extend/tag.js
+++ b/lib/extend/tag.js
@@ -214,6 +214,14 @@ class Tag {
     this.env.addExtension(name, tag);
   }
 
+  unregister(name) {
+    if (!name) throw new TypeError('name is required');
+
+    const { env } = this;
+
+    if (env.hasExtension(name)) env.removeExtension(name);
+  }
+
   render(str, options, callback) {
     if (!callback && typeof options === 'function') {
       callback = options;
diff --git a/test/scripts/extend/tag.js b/test/scripts/extend/tag.js
index 2481ea96b8..1788a12166 100644
--- a/test/scripts/extend/tag.js
+++ b/test/scripts/extend/tag.js
@@ -161,6 +161,37 @@ describe('Tag', () => {
     errorCallback.calledOnce.should.be.true;
   });
 
+  it('unregister()', () => {
+    const tag = new Tag();
+
+    tag.register('test', (args, content) => Promise.resolve(args.join(' ')), {async: true});
+    tag.unregister('test');
+
+    return tag.render('{% test foo bar %}')
+      .then(result => {
+        console.log(result);
+        throw new Error('should return error');
+      })
+      .catch(err => {
+        err.should.have.property('type', 'unknown block tag: test');
+      });
+  });
+
+  it('unregister() - name is required', () => {
+    const errorCallback = sinon.spy(err => {
+      err.should.have.property('message', 'name is required');
+    });
+
+    try {
+      tag.unregister();
+    } catch (err) {
+      errorCallback(err);
+    }
+
+    errorCallback.calledOnce.should.be.true;
+  });
+
+
   it('render() - context', () => {
     const tag = new Tag();