diff --git a/Gruntfile.js b/Gruntfile.js
index 05be6a58a..e4b664fb5 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -133,7 +133,6 @@ module.exports = function(grunt) {
                 src: [
                     // Ensure editor source files are concatenated in
                     // the right order
-                    "packages/node_modules/@node-red/editor-client/src/js/polyfills.js",
                     "packages/node_modules/@node-red/editor-client/src/js/jquery-addons.js",
                     "packages/node_modules/@node-red/editor-client/src/js/red.js",
                     "packages/node_modules/@node-red/editor-client/src/js/events.js",
diff --git a/packages/node_modules/@node-red/editor-client/src/js/polyfills.js b/packages/node_modules/@node-red/editor-client/src/js/polyfills.js
deleted file mode 100644
index 100cd4913..000000000
--- a/packages/node_modules/@node-red/editor-client/src/js/polyfills.js
+++ /dev/null
@@ -1,56 +0,0 @@
-(function() {
-    var isIE11 = !!window.MSInputMethodContext && !!document.documentMode;
-
-    if (isIE11) {
-        // IE11 DOMTokenList.toggle does not support the two-argument variety
-        window.DOMTokenList.prototype.toggle = function(cl,bo) {
-            if (arguments.length === 1) {
-                bo = !this.contains(cl);
-            }
-            this[!!bo?"add":"remove"](cl);
-        }
-
-        // IE11 does not provide classList on SVGElements
-        if (! ("classList" in SVGElement.prototype)) {
-            Object.defineProperty(SVGElement.prototype, 'classList', Object.getOwnPropertyDescriptor(HTMLElement.prototype, 'classList'));
-        }
-
-        // IE11 does not provide children on SVGElements
-        if (! ("children" in SVGElement.prototype)) {
-            Object.defineProperty(SVGElement.prototype, 'children', Object.getOwnPropertyDescriptor(HTMLElement.prototype, 'children'));
-        }
-
-        Array.from = function() {
-            if (arguments.length > 1) {
-                throw new Error("Node-RED's IE11 Array.from polyfill doesn't support multiple arguments");
-            }
-            var arrayLike = arguments[0]
-            var result = [];
-            if (arrayLike.forEach) {
-                arrayLike.forEach(function(i) {
-                    result.push(i);
-                })
-            } else {
-                for (var i=0;i<arrayLike.length;i++) {
-                    result.push(arrayList[i]);
-                }
-            }
-            return result;
-        }
-
-        if (new Set([0]).size === 0) {
-            // IE does not support passing an iterable to Set constructor
-            var _Set = Set;
-            /*global Set:true */
-            Set = function Set(iterable) {
-                var set = new _Set();
-                if (iterable) {
-                    iterable.forEach(set.add, set);
-                }
-                return set;
-            };
-            Set.prototype = _Set.prototype;
-            Set.prototype.constructor = Set;
-        }
-    }
-})();
diff --git a/packages/node_modules/@node-red/editor-client/src/js/ui/clipboard.js b/packages/node_modules/@node-red/editor-client/src/js/ui/clipboard.js
index 4e16bd3f6..4089e392e 100644
--- a/packages/node_modules/@node-red/editor-client/src/js/ui/clipboard.js
+++ b/packages/node_modules/@node-red/editor-client/src/js/ui/clipboard.js
@@ -34,23 +34,13 @@ RED.clipboard = (function() {
 
 
     function downloadData(file, data) {
-        if (window.navigator.msSaveBlob) {
-            // IE11 workaround
-            // IE does not support data uri scheme for downloading data
-            var blob = new Blob([data], {
-                type: "data:application/json;charset=utf-8"
-            });
-            navigator.msSaveBlob(blob, file);
-        }
-        else {
-            var element = document.createElement('a');
-            element.setAttribute('href', 'data:application/json;charset=utf-8,' + encodeURIComponent(data));
-            element.setAttribute('download', file);
-            element.style.display = 'none';
-            document.body.appendChild(element);
-            element.click();
-            document.body.removeChild(element);
-        }
+        const element = document.createElement('a');
+        element.setAttribute('href', 'data:application/json;charset=utf-8,' + encodeURIComponent(data));
+        element.setAttribute('download', file);
+        element.style.display = 'none';
+        document.body.appendChild(element);
+        element.click();
+        document.body.removeChild(element);
     }
 
     function setupDialogs() {