diff --git a/CHANGES.MD b/CHANGES.MD
index a26e510..b89b2a2 100644
--- a/CHANGES.MD
+++ b/CHANGES.MD
@@ -1,11 +1,16 @@
 
+## 2.3.1
+
+Fix busted build with evergreen browsers (oops!).
+
 ## 2.3.0
 
 Update build to use rollup, there are now 3 supported bunldes:
 
-- fireworks.js - cjs module
+- fireworks.node.js - cjs module
 - fireworks.mjs - es6 module
-- fireworks.umd.js - browser umd bundle
+- fireworks.js - browser umd bundle
+- fireworks.min.js - browser umd bundle (minified)
 
 The browser bundle now has a target of `es3` so it should support older browsers.
 
diff --git a/README.MD b/README.MD
index df6d831..9e6b8af 100644
--- a/README.MD
+++ b/README.MD
@@ -17,7 +17,7 @@ import * as Fireworks from 'fireworks-canvas' // mjs
 
 const Fireworks = require('fireworks-canvas') // cjs
 
-define(['fireworks'], (Fireworks) =>  {}) // amd
+requirejs(['Fireworks'], (Fireworks) =>  {}) // amd
 
 const Fireworks = window.Fireworks // browser global
 
diff --git a/fireworks.js b/fireworks.js
index bb8dde0..a1195f6 100644
--- a/fireworks.js
+++ b/fireworks.js
@@ -18,20 +18,6 @@
     See the Apache Version 2.0 License for specific language governing permissions
     and limitations under the License.
     ***************************************************************************** */
-    /* global Reflect, Promise */
-
-    var extendStatics = function(d, b) {
-        extendStatics = Object.setPrototypeOf ||
-            ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
-            function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
-        return extendStatics(d, b);
-    };
-
-    function __extends(d, b) {
-        extendStatics(d, b);
-        function __() { this.constructor = d; }
-        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
-    }
 
     function __values(o) {
         var m = typeof Symbol === "function" && o[Symbol.iterator], i = 0;
@@ -141,18 +127,31 @@
         return Particle;
     }());
 
-    var Things = (function (_super) {
-        __extends(Things, _super);
+    var Things = (function () {
         function Things(_a) {
             var maxRockets = _a.maxRockets, numParticles = _a.numParticles, cw = _a.cw, ch = _a.ch;
-            var _this = _super.call(this) || this;
-            _this.rockets = 0;
-            _this.maxRockets = maxRockets;
-            _this.numParticles = numParticles;
-            _this.cw = cw;
-            _this.ch = ch;
-            return _this;
+            this._set = new Set();
+            this.rockets = 0;
+            this.maxRockets = maxRockets;
+            this.numParticles = numParticles;
+            this.cw = cw;
+            this.ch = ch;
         }
+        Things.prototype.size = function () {
+            return this._set.size;
+        };
+        Things.prototype.entries = function () {
+            return this._set;
+        };
+        Things.prototype.clear = function () {
+            this._set.clear();
+        };
+        Things.prototype["delete"] = function (thing) {
+            this._set["delete"](thing);
+        };
+        Things.prototype.add = function (thing) {
+            this._set.add(thing);
+        };
         Things.prototype.explode = function (particle) {
             this.rockets--;
             for (var i = 0; i < this.numParticles; i += 1) {
@@ -176,7 +175,7 @@
             }
         };
         return Things;
-    }(Set));
+    }());
 
     var Fireworks = (function () {
         function Fireworks(container, _a) {
@@ -208,7 +207,7 @@
         Fireworks.prototype.start = function () {
             var _this = this;
             if (this.maxRockets > 0) {
-                this.interval = setInterval(function () { return _this.things.spawnRockets(); }, this.rocketSpawnInterval);
+                this.interval = window.setInterval(function () { return _this.things.spawnRockets(); }, this.rocketSpawnInterval);
                 this.rafInterval = window.requestAnimationFrame(function () { return _this.update(); });
             }
             return function () { return _this.stop(); };
@@ -243,7 +242,7 @@
             var e_1, _a;
             this._clear();
             try {
-                for (var _b = __values(this.things), _c = _b.next(); !_c.done; _c = _b.next()) {
+                for (var _b = __values(this.things.entries()), _c = _b.next(); !_c.done; _c = _b.next()) {
                     var particle = _c.value;
                     particle.draw(this.ctx);
                     particle.update();
@@ -262,7 +261,7 @@
                 }
                 finally { if (e_1) throw e_1.error; }
             }
-            if (this.interval || this.things.size > 0) {
+            if (this.interval || this.things.size() > 0) {
                 this.rafInterval = window.requestAnimationFrame(function () { return _this.update(); });
             }
             else {
diff --git a/fireworks.min.js b/fireworks.min.js
index 3b69f70..b53c830 100644
--- a/fireworks.min.js
+++ b/fireworks.min.js
@@ -1 +1 @@
-!function(t,i){"object"==typeof exports&&"undefined"!=typeof module?module.exports=i():"function"==typeof define&&define.amd?define("Fireworks",i):t.Fireworks=i()}(this,function(){"use strict";var t=function(i,s){return(t=Object.setPrototypeOf||{__proto__:[]}instanceof Array&&function(t,i){t.__proto__=i}||function(t,i){for(var s in i)i.hasOwnProperty(s)&&(t[s]=i[s])})(i,s)};function i(t,i){return Math.random()*(i-t)+t}var s=2*Math.PI,o=function(){function t(t){var o=t.isRocket,n=void 0!==o&&o,e=t.hue,h=void 0===e?i(1,360):e,r=t.brightness,a=void 0===r?i(50,60):r,c=t.position;if(this.isRocket=n,this.position=c,this.positions=[this.position,this.position,this.position],this.isRocket)this.velocity={x:i(-3,3),y:i(-7,-3)},this.shrink=.999,this.resistance=1;else{var p=i(0,s),l=15*Math.cos(i(0,s));this.velocity={x:Math.cos(p)*l,y:Math.sin(p)*l},this.shrink=i(0,.05)+.93,this.resistance=.92}this.gravity=.01,this.size=3,this.alpha=1,this.fade=0,this.hue=h,this.brightness=a}return t.prototype.clone=function(){return new t({position:{x:this.position.x,y:this.position.y},hue:this.hue,brightness:this.brightness})},t.prototype.shouldRemove=function(t,i){return this.alpha<=.1||this.size<=1||(this.position.x>t||this.position.x<0||(this.position.y>i||this.position.y<0))},t.prototype.shouldExplode=function(t,s,o){return!!this.isRocket&&(this.position.y<=t||!(this.position.y>=s)&&i(0,1)<=o)},t.prototype.update=function(){this.positions.pop(),this.positions.unshift({x:this.position.x,y:this.position.y}),this.velocity.x*=this.resistance,this.velocity.y*=this.resistance,this.velocity.y+=this.gravity,this.position.x+=this.velocity.x,this.position.y+=this.velocity.y,this.size*=this.shrink,this.alpha-=this.fade},t.prototype.draw=function(t){var i=this.positions[this.positions.length-1];t.beginPath(),t.moveTo(i.x,i.y),t.lineTo(this.position.x,this.position.y),t.lineWidth=this.size,t.strokeStyle="hsla("+this.hue+", 100%, "+this.brightness+"%, "+this.alpha+")",t.stroke()},t}(),n=function(s){function n(t){var i=t.maxRockets,o=t.numParticles,n=t.cw,e=t.ch,h=s.call(this)||this;return h.rockets=0,h.maxRockets=i,h.numParticles=o,h.cw=n,h.ch=e,h}return function(i,s){function o(){this.constructor=i}t(i,s),i.prototype=null===s?Object.create(s):(o.prototype=s.prototype,new o)}(n,s),n.prototype.explode=function(t){this.rockets--;for(var i=0;i<this.numParticles;i+=1)this.add(t.clone());this.delete(t)},n.prototype.spawnRocket=function(){this.rockets++,this.add(new o({isRocket:!0,position:{x:i(0,this.cw),y:this.ch}}))},n.prototype.spawnRockets=function(){this.rockets<this.maxRockets&&this.spawnRocket()},n}(Set);return function(){function t(t,i){var s=void 0===i?{}:i,o=s.rocketSpawnInterval,e=void 0===o?150:o,h=s.maxRockets,r=void 0===h?3:h,a=s.numParticles,c=void 0===a?100:a,p=s.explosionMinHeight,l=void 0===p?.2:p,u=s.explosionMaxHeight,f=void 0===u?.9:u,v=s.explosionChance,d=void 0===v?.08:v;this.rocketSpawnInterval=e,this.maxRockets=r,this.cw=t.clientWidth,this.ch=t.clientHeight,this.max_h=this.ch*(1-f),this.min_h=this.ch*(1-l),this.chance=d,this.canvas=document.createElement("canvas"),this.canvas.width=this.cw,this.canvas.height=this.ch,this.ctx=this.canvas.getContext("2d"),t.appendChild(this.canvas),this.things=new n({maxRockets:this.maxRockets,numParticles:c,cw:this.cw,ch:this.ch})}return t.prototype.destroy=function(){this.canvas.parentElement.removeChild(this.canvas),window.clearInterval(this.interval),window.cancelAnimationFrame(this.rafInterval)},t.prototype.start=function(){var t=this;return this.maxRockets>0&&(this.interval=setInterval(function(){return t.things.spawnRockets()},this.rocketSpawnInterval),this.rafInterval=window.requestAnimationFrame(function(){return t.update()})),function(){return t.stop()}},t.prototype.stop=function(){window.clearInterval(this.interval),this.interval=null},t.prototype.kill=function(){this.things.clear(),this.stop(),window.cancelAnimationFrame(this.rafInterval),this.rafInterval=null,this._clear(!0)},t.prototype.fire=function(){var t=this;this.things.spawnRocket(),this.rafInterval||(this.rafInterval=window.requestAnimationFrame(function(){return t.update()}))},t.prototype._clear=function(t){void 0===t&&(t=!1),this.ctx.globalCompositeOperation="destination-out",this.ctx.fillStyle="rgba(0, 0, 0 "+(t?"":", 0.5")+")",this.ctx.fillRect(0,0,this.cw,this.ch),this.ctx.globalCompositeOperation="lighter"},t.prototype.update=function(){var t,i,s=this;this._clear();try{for(var o=function(t){var i="function"==typeof Symbol&&t[Symbol.iterator],s=0;return i?i.call(t):{next:function(){return t&&s>=t.length&&(t=void 0),{value:t&&t[s++],done:!t}}}}(this.things),n=o.next();!n.done;n=o.next()){var e=n.value;e.draw(this.ctx),e.update(),e.shouldRemove(this.cw,this.ch)?this.things.delete(e):e.shouldExplode(this.max_h,this.min_h,this.chance)&&this.things.explode(e)}}catch(i){t={error:i}}finally{try{n&&!n.done&&(i=o.return)&&i.call(o)}finally{if(t)throw t.error}}this.interval||this.things.size>0?this.rafInterval=window.requestAnimationFrame(function(){return s.update()}):(this._clear(!0),this.rafInterval=null)},t}()});
+!function(t,i){"object"==typeof exports&&"undefined"!=typeof module?module.exports=i():"function"==typeof define&&define.amd?define("Fireworks",i):t.Fireworks=i()}(this,function(){"use strict";function t(t,i){return Math.random()*(i-t)+t}var i=2*Math.PI,s=function(){function s(s){var e=s.isRocket,n=void 0!==e&&e,o=s.hue,h=void 0===o?t(1,360):o,r=s.brightness,a=void 0===r?t(50,60):r,c=s.position;if(this.isRocket=n,this.position=c,this.positions=[this.position,this.position,this.position],this.isRocket)this.velocity={x:t(-3,3),y:t(-7,-3)},this.shrink=.999,this.resistance=1;else{var p=t(0,i),l=15*Math.cos(t(0,i));this.velocity={x:Math.cos(p)*l,y:Math.sin(p)*l},this.shrink=t(0,.05)+.93,this.resistance=.92}this.gravity=.01,this.size=3,this.alpha=1,this.fade=0,this.hue=h,this.brightness=a}return s.prototype.clone=function(){return new s({position:{x:this.position.x,y:this.position.y},hue:this.hue,brightness:this.brightness})},s.prototype.shouldRemove=function(t,i){return this.alpha<=.1||this.size<=1||(this.position.x>t||this.position.x<0||(this.position.y>i||this.position.y<0))},s.prototype.shouldExplode=function(i,s,e){return!!this.isRocket&&(this.position.y<=i||!(this.position.y>=s)&&t(0,1)<=e)},s.prototype.update=function(){this.positions.pop(),this.positions.unshift({x:this.position.x,y:this.position.y}),this.velocity.x*=this.resistance,this.velocity.y*=this.resistance,this.velocity.y+=this.gravity,this.position.x+=this.velocity.x,this.position.y+=this.velocity.y,this.size*=this.shrink,this.alpha-=this.fade},s.prototype.draw=function(t){var i=this.positions[this.positions.length-1];t.beginPath(),t.moveTo(i.x,i.y),t.lineTo(this.position.x,this.position.y),t.lineWidth=this.size,t.strokeStyle="hsla("+this.hue+", 100%, "+this.brightness+"%, "+this.alpha+")",t.stroke()},s}(),e=function(){function i(t){var i=t.maxRockets,s=t.numParticles,e=t.cw,n=t.ch;this._set=new Set,this.rockets=0,this.maxRockets=i,this.numParticles=s,this.cw=e,this.ch=n}return i.prototype.size=function(){return this._set.size},i.prototype.entries=function(){return this._set},i.prototype.clear=function(){this._set.clear()},i.prototype.delete=function(t){this._set.delete(t)},i.prototype.add=function(t){this._set.add(t)},i.prototype.explode=function(t){this.rockets--;for(var i=0;i<this.numParticles;i+=1)this.add(t.clone());this.delete(t)},i.prototype.spawnRocket=function(){this.rockets++,this.add(new s({isRocket:!0,position:{x:t(0,this.cw),y:this.ch}}))},i.prototype.spawnRockets=function(){this.rockets<this.maxRockets&&this.spawnRocket()},i}();return function(){function t(t,i){var s=void 0===i?{}:i,n=s.rocketSpawnInterval,o=void 0===n?150:n,h=s.maxRockets,r=void 0===h?3:h,a=s.numParticles,c=void 0===a?100:a,p=s.explosionMinHeight,l=void 0===p?.2:p,u=s.explosionMaxHeight,d=void 0===u?.9:u,v=s.explosionChance,f=void 0===v?.08:v;this.rocketSpawnInterval=o,this.maxRockets=r,this.cw=t.clientWidth,this.ch=t.clientHeight,this.max_h=this.ch*(1-d),this.min_h=this.ch*(1-l),this.chance=f,this.canvas=document.createElement("canvas"),this.canvas.width=this.cw,this.canvas.height=this.ch,this.ctx=this.canvas.getContext("2d"),t.appendChild(this.canvas),this.things=new e({maxRockets:this.maxRockets,numParticles:c,cw:this.cw,ch:this.ch})}return t.prototype.destroy=function(){this.canvas.parentElement.removeChild(this.canvas),window.clearInterval(this.interval),window.cancelAnimationFrame(this.rafInterval)},t.prototype.start=function(){var t=this;return this.maxRockets>0&&(this.interval=window.setInterval(function(){return t.things.spawnRockets()},this.rocketSpawnInterval),this.rafInterval=window.requestAnimationFrame(function(){return t.update()})),function(){return t.stop()}},t.prototype.stop=function(){window.clearInterval(this.interval),this.interval=null},t.prototype.kill=function(){this.things.clear(),this.stop(),window.cancelAnimationFrame(this.rafInterval),this.rafInterval=null,this._clear(!0)},t.prototype.fire=function(){var t=this;this.things.spawnRocket(),this.rafInterval||(this.rafInterval=window.requestAnimationFrame(function(){return t.update()}))},t.prototype._clear=function(t){void 0===t&&(t=!1),this.ctx.globalCompositeOperation="destination-out",this.ctx.fillStyle="rgba(0, 0, 0 "+(t?"":", 0.5")+")",this.ctx.fillRect(0,0,this.cw,this.ch),this.ctx.globalCompositeOperation="lighter"},t.prototype.update=function(){var t,i,s=this;this._clear();try{for(var e=function(t){var i="function"==typeof Symbol&&t[Symbol.iterator],s=0;return i?i.call(t):{next:function(){return t&&s>=t.length&&(t=void 0),{value:t&&t[s++],done:!t}}}}(this.things.entries()),n=e.next();!n.done;n=e.next()){var o=n.value;o.draw(this.ctx),o.update(),o.shouldRemove(this.cw,this.ch)?this.things.delete(o):o.shouldExplode(this.max_h,this.min_h,this.chance)&&this.things.explode(o)}}catch(i){t={error:i}}finally{try{n&&!n.done&&(i=e.return)&&i.call(e)}finally{if(t)throw t.error}}this.interval||this.things.size()>0?this.rafInterval=window.requestAnimationFrame(function(){return s.update()}):(this._clear(!0),this.rafInterval=null)},t}()});
diff --git a/fireworks.mjs b/fireworks.mjs
index f2501f6..0c7ce80 100644
--- a/fireworks.mjs
+++ b/fireworks.mjs
@@ -93,15 +93,30 @@ class Particle {
     }
 }
 
-class Things extends Set {
+class Things {
     constructor({ maxRockets, numParticles, cw, ch }) {
-        super();
+        this._set = new Set();
         this.rockets = 0;
         this.maxRockets = maxRockets;
         this.numParticles = numParticles;
         this.cw = cw;
         this.ch = ch;
     }
+    size() {
+        return this._set.size;
+    }
+    entries() {
+        return this._set;
+    }
+    clear() {
+        this._set.clear();
+    }
+    delete(thing) {
+        this._set.delete(thing);
+    }
+    add(thing) {
+        this._set.add(thing);
+    }
     explode(particle) {
         this.rockets--;
         for (let i = 0; i < this.numParticles; i += 1) {
@@ -154,7 +169,7 @@ class Fireworks {
     }
     start() {
         if (this.maxRockets > 0) {
-            this.interval = setInterval(() => this.things.spawnRockets(), this.rocketSpawnInterval);
+            this.interval = window.setInterval(() => this.things.spawnRockets(), this.rocketSpawnInterval);
             this.rafInterval = window.requestAnimationFrame(() => this.update());
         }
         return () => this.stop();
@@ -184,7 +199,7 @@ class Fireworks {
     }
     update() {
         this._clear();
-        for (const particle of this.things) {
+        for (const particle of this.things.entries()) {
             particle.draw(this.ctx);
             particle.update();
             if (particle.shouldRemove(this.cw, this.ch)) {
@@ -194,7 +209,7 @@ class Fireworks {
                 this.things.explode(particle);
             }
         }
-        if (this.interval || this.things.size > 0) {
+        if (this.interval || this.things.size() > 0) {
             this.rafInterval = window.requestAnimationFrame(() => this.update());
         }
         else {
diff --git a/fireworks.node.js b/fireworks.node.js
index 4fe29f9..5e76472 100644
--- a/fireworks.node.js
+++ b/fireworks.node.js
@@ -95,15 +95,30 @@ class Particle {
     }
 }
 
-class Things extends Set {
+class Things {
     constructor({ maxRockets, numParticles, cw, ch }) {
-        super();
+        this._set = new Set();
         this.rockets = 0;
         this.maxRockets = maxRockets;
         this.numParticles = numParticles;
         this.cw = cw;
         this.ch = ch;
     }
+    size() {
+        return this._set.size;
+    }
+    entries() {
+        return this._set;
+    }
+    clear() {
+        this._set.clear();
+    }
+    delete(thing) {
+        this._set.delete(thing);
+    }
+    add(thing) {
+        this._set.add(thing);
+    }
     explode(particle) {
         this.rockets--;
         for (let i = 0; i < this.numParticles; i += 1) {
@@ -156,7 +171,7 @@ class Fireworks {
     }
     start() {
         if (this.maxRockets > 0) {
-            this.interval = setInterval(() => this.things.spawnRockets(), this.rocketSpawnInterval);
+            this.interval = window.setInterval(() => this.things.spawnRockets(), this.rocketSpawnInterval);
             this.rafInterval = window.requestAnimationFrame(() => this.update());
         }
         return () => this.stop();
@@ -186,7 +201,7 @@ class Fireworks {
     }
     update() {
         this._clear();
-        for (const particle of this.things) {
+        for (const particle of this.things.entries()) {
             particle.draw(this.ctx);
             particle.update();
             if (particle.shouldRemove(this.cw, this.ch)) {
@@ -196,7 +211,7 @@ class Fireworks {
                 this.things.explode(particle);
             }
         }
-        if (this.interval || this.things.size > 0) {
+        if (this.interval || this.things.size() > 0) {
             this.rafInterval = window.requestAnimationFrame(() => this.update());
         }
         else {
diff --git a/package.json b/package.json
index 7c1bb5d..1723b49 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "fireworks-canvas",
-  "version": "2.3.0",
+  "version": "2.3.1",
   "description": "fireworks example",
   "browser": "./fireworks.min.js",
   "main": "./fireworks.node.js",