diff --git a/src/ol/interaction/mousewheelzoom.js b/src/ol/interaction/mousewheelzoom.js
index c5acd21cfc..04acd0388d 100644
--- a/src/ol/interaction/mousewheelzoom.js
+++ b/src/ol/interaction/mousewheelzoom.js
@@ -116,7 +116,6 @@ ol.interaction.MouseWheelZoom.handleEvent = function(mapBrowserEvent) {
 
   // Delta normalisation inspired by
   // https://github.com/mapbox/mapbox-gl-js/blob/001c7b9/js/ui/handler/scroll_zoom.js
-  //TODO There's more good stuff in there for inspiration to improve this interaction.
   var delta;
   if (mapBrowserEvent.type == ol.events.EventType.WHEEL) {
     delta = wheelEvent.deltaY;
diff --git a/test/spec/ol/interaction/mousewheelzoom.test.js b/test/spec/ol/interaction/mousewheelzoom.test.js
index c2aebc5e06..f76f0469a3 100644
--- a/test/spec/ol/interaction/mousewheelzoom.test.js
+++ b/test/spec/ol/interaction/mousewheelzoom.test.js
@@ -7,14 +7,17 @@ goog.require('ol.View');
 goog.require('ol.events.Event');
 goog.require('ol.has');
 goog.require('ol.interaction.Interaction');
+goog.require('ol.interaction.MouseWheelZoom');
 
 
 describe('ol.interaction.MouseWheelZoom', function() {
-  var map;
+  var map, interaction;
 
   beforeEach(function() {
+    interaction = new ol.interaction.MouseWheelZoom();
     map = new ol.Map({
       target: createMapDiv(100, 100),
+      interactions: [interaction],
       view: new ol.View({
         center: [0, 0],
         resolutions: [2, 1, 0.5],
@@ -23,8 +26,11 @@ describe('ol.interaction.MouseWheelZoom', function() {
     });
     map.renderSync();
   });
+
   afterEach(function() {
     disposeMap(map);
+    map = null;
+    interaction = null;
   });
 
   describe('timeout duration', function() {
@@ -58,14 +64,12 @@ describe('ol.interaction.MouseWheelZoom', function() {
   });
 
   describe('handleEvent()', function() {
-    it('[wheel] works on Firefox in DOM_DELTA_PIXEL mode', function(done) {
+
+    it('works on Firefox in DOM_DELTA_PIXEL mode (trackpad)', function(done) {
       var origHasFirefox = ol.has.FIREFOX;
       ol.has.FIREFOX = true;
-      var spy = sinon.spy(ol.interaction.Interaction, 'zoomByDelta');
       map.once('postrender', function() {
-        expect(spy.getCall(0).args[2]).to.be(-1);
-        expect(spy.getCall(0).args[3]).to.eql([0, 0]);
-        ol.interaction.Interaction.zoomByDelta.restore();
+        expect(interaction.mode_).to.be(ol.interaction.MouseWheelZoom.Mode.TRACKPAD);
         ol.has.FIREFOX = origHasFirefox;
         done();
       });
@@ -79,14 +83,12 @@ describe('ol.interaction.MouseWheelZoom', function() {
       event.coordinate = [0, 0];
       map.handleMapBrowserEvent(event);
     });
-    it('[wheel] works in DOM_DELTA_PIXEL mode', function(done) {
+
+    it('works in DOM_DELTA_PIXEL mode (trackpad)', function(done) {
       var origHasFirefox = ol.has.FIREFOX;
       ol.has.FIREFOX = false;
-      var spy = sinon.spy(ol.interaction.Interaction, 'zoomByDelta');
       map.once('postrender', function() {
-        expect(spy.getCall(0).args[2]).to.be(-1);
-        expect(spy.getCall(0).args[3]).to.eql([0, 0]);
-        ol.interaction.Interaction.zoomByDelta.restore();
+        expect(interaction.mode_).to.be(ol.interaction.MouseWheelZoom.Mode.TRACKPAD);
         ol.has.FIREFOX = origHasFirefox;
         done();
       });
@@ -100,7 +102,8 @@ describe('ol.interaction.MouseWheelZoom', function() {
       event.coordinate = [0, 0];
       map.handleMapBrowserEvent(event);
     });
-    it('[wheel] works in DOM_DELTA_LINE mode', function(done) {
+
+    it('works in DOM_DELTA_LINE mode (wheel)', function(done) {
       var spy = sinon.spy(ol.interaction.Interaction, 'zoomByDelta');
       map.once('postrender', function() {
         expect(spy.getCall(0).args[2]).to.be(-1);
@@ -111,14 +114,15 @@ describe('ol.interaction.MouseWheelZoom', function() {
       var event = new ol.MapBrowserEvent('wheel', map, {
         type: 'wheel',
         deltaMode: WheelEvent.DOM_DELTA_LINE,
-        deltaY: 1 / 40,
+        deltaY: 3.714599609375,
         target: map.getViewport(),
         preventDefault: ol.events.Event.prototype.preventDefault
       });
       event.coordinate = [0, 0];
       map.handleMapBrowserEvent(event);
     });
-    it('[mousewheel] works on Safari', function(done) {
+
+    it('works on Safari (wheel)', function(done) {
       var origHasSafari = ol.has.SAFARI;
       ol.has.SAFARI = true;
       var spy = sinon.spy(ol.interaction.Interaction, 'zoomByDelta');
@@ -131,14 +135,15 @@ describe('ol.interaction.MouseWheelZoom', function() {
       });
       var event = new ol.MapBrowserEvent('mousewheel', map, {
         type: 'mousewheel',
-        wheelDeltaY: -3,
+        wheelDeltaY: -50,
         target: map.getViewport(),
         preventDefault: ol.events.Event.prototype.preventDefault
       });
       event.coordinate = [0, 0];
       map.handleMapBrowserEvent(event);
     });
-    it('[mousewheel] works on other browsers', function(done) {
+
+    it('works on other browsers (wheel)', function(done) {
       var origHasSafari = ol.has.SAFARI;
       ol.has.SAFARI = false;
       var spy = sinon.spy(ol.interaction.Interaction, 'zoomByDelta');
@@ -151,7 +156,7 @@ describe('ol.interaction.MouseWheelZoom', function() {
       });
       var event = new ol.MapBrowserEvent('mousewheel', map, {
         type: 'mousewheel',
-        wheelDeltaY: -1,
+        wheelDeltaY: -120,
         target: map.getViewport(),
         preventDefault: ol.events.Event.prototype.preventDefault
       });