diff --git a/.gitignore b/.gitignore
index 3c6d099f..42b64dde 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,3 +10,5 @@ node_modules
 *.sublime-workspace
 npm-debug.log
 sauce_connect.log*
+.idea
+yarn-error.log
diff --git a/Gruntfile.js b/Gruntfile.js
index 25e1f1bd..be8e3ab0 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -183,7 +183,7 @@ module.exports = function(grunt) {
   grunt.task.loadTasks('tasks');
 
   grunt.registerTask('bench', ['metrics']);
-  grunt.registerTask('sauce', process.env.SAUCE_USERNAME ? ['tests', 'connect', 'saucelabs-mocha'] : []);
+  grunt.registerTask('sauce', [] /* process.env.SAUCE_USERNAME ? ['tests', 'connect', 'saucelabs-mocha'] : [] */);
 
   grunt.registerTask('travis', process.env.PUBLISH ? ['default', 'sauce', 'metrics', 'publish:latest'] : ['default']);
 
diff --git a/appveyor.yml b/appveyor.yml
index b67fb4ca..563aaf93 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,8 +1,7 @@
 # Test against these versions of Node.js
 environment:
   matrix:
-    - nodejs_version: "4"
-    - nodejs_version: "5"
+    - nodejs_version: "10"
 
 platform:
   - x64
diff --git a/lib/handlebars/base.js b/lib/handlebars/base.js
index 127be4b7..22307b9d 100644
--- a/lib/handlebars/base.js
+++ b/lib/handlebars/base.js
@@ -4,7 +4,7 @@ import {registerDefaultHelpers} from './helpers';
 import {registerDefaultDecorators} from './decorators';
 import logger from './logger';
 
-export const VERSION = '4.0.12';
+export const VERSION = '4.1.0';
 export const COMPILER_REVISION = 7;
 
 export const REVISION_CHANGES = {
diff --git a/lib/handlebars/compiler/javascript-compiler.js b/lib/handlebars/compiler/javascript-compiler.js
index 551ddbb2..d6ba5410 100644
--- a/lib/handlebars/compiler/javascript-compiler.js
+++ b/lib/handlebars/compiler/javascript-compiler.js
@@ -13,6 +13,9 @@ JavaScriptCompiler.prototype = {
   // PUBLIC API: You can override these methods in a subclass to provide
   // alternative compiled forms for name lookup and buffering semantics
   nameLookup: function(parent, name/* , type*/) {
+    if (name === 'constructor') {
+      return ['(', parent, '.propertyIsEnumerable(\'constructor\') ? ', parent, '.constructor : undefined', ')'];
+    }
     if (JavaScriptCompiler.isValidJavaScriptVariableName(name)) {
       return [parent, '.', name];
     } else {
diff --git a/package.json b/package.json
index 6120b26a..7553b2cf 100644
--- a/package.json
+++ b/package.json
@@ -46,7 +46,7 @@
     "grunt-contrib-uglify": "^1",
     "grunt-contrib-watch": "^1.1.0",
     "grunt-eslint": "^20.1.0",
-    "grunt-saucelabs": "8.x",
+    "grunt-saucelabs": "9.x",
     "grunt-webpack": "^1.0.8",
     "istanbul": "kpdecker/istanbul",
     "jison": "0.4.16",
diff --git a/release-notes.md b/release-notes.md
index 782aace3..681bde43 100644
--- a/release-notes.md
+++ b/release-notes.md
@@ -2,7 +2,44 @@
 
 ## Development
 
-[Commits](https://github.com/wycats/handlebars.js/compare/v4.0.12...master)
+[Commits](https://github.com/wycats/handlebars.js/compare/v4.1.0...master)
+
+## v4.1.0 - February 7th, 2019
+New Features
+
+- import TypeScript typings - 27ac1ee
+
+Security fixes:
+
+- disallow access to the constructor in templates to prevent RCE - 42841c4, #1495
+
+Housekeeping
+
+- chore: fix components/handlebars package.json and auto-update on release - bacd473
+- chore: Use node 10 to build handlebars - 78dd89c
+- chore/doc: Add more release docs - 6b87c21
+
+Compatibility notes:
+
+Access to class constructors (i.e. `({}).constructor`) is now prohibited to prevent
+Remote Code Execution. This means that following construct will no work anymore:
+
+```
+class SomeClass {
+}
+
+SomeClass.staticProperty = 'static'
+
+var template = Handlebars.compile('{{constructor.staticProperty}}');
+document.getElementById('output').innerHTML = template(new SomeClass());
+// expected: 'static', but now this is empty.
+```
+
+This kind of access is not the intended use of Handlebars and leads to the vulnerability described in #1495. We will **not** increase the major version, because such use is not intended or documented, and because of the potential impact of the issue (we fear that most people won't use a new major version and the issue may not be resolved on many systems).
+
+
+
+[Commits](https://github.com/wycats/handlebars.js/compare/v4.0.12...v4.1.0)
 
 ## v4.0.12 - September 4th, 2018
 New features:
diff --git a/spec/security.js b/spec/security.js
new file mode 100644
index 00000000..45b96c34
--- /dev/null
+++ b/spec/security.js
@@ -0,0 +1,23 @@
+describe('security issues', function() {
+    describe('GH-1495: Prevent Remote Code Execution via constructor', function() {
+        it('should not allow constructors to be accessed', function() {
+            shouldCompileTo('{{constructor.name}}', {}, '');
+        });
+
+        it('should allow the "constructor" property to be accessed if it is enumerable', function() {
+            shouldCompileTo('{{constructor.name}}', {'constructor': {
+                'name': 'here we go'
+            }}, 'here we go');
+        });
+
+        it('should allow prototype properties that are not constructors', function() {
+            class TestClass {
+                get abc() {
+                    return 'xyz';
+                }
+            }
+            shouldCompileTo('{{#with this as |obj|}}{{obj.abc}}{{/with}}',
+                new TestClass(), 'xyz');
+        });
+    });
+});