diff --git a/src/ol/Overlay.js b/src/ol/Overlay.js
index fc2011af20..674664f25d 100644
--- a/src/ol/Overlay.js
+++ b/src/ol/Overlay.js
@@ -45,7 +45,7 @@ var Property = {
  * @param {olx.OverlayOptions} options Overlay options.
  * @api
  */
-var _ol_Overlay_ = function(options) {
+var Overlay = function(options) {
 
   _ol_Object_.call(this);
 
@@ -161,7 +161,7 @@ var _ol_Overlay_ = function(options) {
 
 };
 
-inherits(_ol_Overlay_, _ol_Object_);
+inherits(Overlay, _ol_Object_);
 
 
 /**
@@ -170,7 +170,7 @@ inherits(_ol_Overlay_, _ol_Object_);
  * @observable
  * @api
  */
-_ol_Overlay_.prototype.getElement = function() {
+Overlay.prototype.getElement = function() {
   return (/** @type {Element|undefined} */ this.get(Property.ELEMENT));
 };
 
@@ -180,7 +180,7 @@ _ol_Overlay_.prototype.getElement = function() {
  * @return {number|string|undefined} Id.
  * @api
  */
-_ol_Overlay_.prototype.getId = function() {
+Overlay.prototype.getId = function() {
   return this.id;
 };
 
@@ -191,7 +191,7 @@ _ol_Overlay_.prototype.getId = function() {
  * @observable
  * @api
  */
-_ol_Overlay_.prototype.getMap = function() {
+Overlay.prototype.getMap = function() {
   return (/** @type {ol.PluggableMap|undefined} */ this.get(Property.MAP));
 };
 
@@ -202,7 +202,7 @@ _ol_Overlay_.prototype.getMap = function() {
  * @observable
  * @api
  */
-_ol_Overlay_.prototype.getOffset = function() {
+Overlay.prototype.getOffset = function() {
   return (/** @type {Array.<number>} */ this.get(Property.OFFSET));
 };
 
@@ -214,7 +214,7 @@ _ol_Overlay_.prototype.getOffset = function() {
  * @observable
  * @api
  */
-_ol_Overlay_.prototype.getPosition = function() {
+Overlay.prototype.getPosition = function() {
   return (/** @type {ol.Coordinate|undefined} */ this.get(Property.POSITION));
 };
 
@@ -226,7 +226,7 @@ _ol_Overlay_.prototype.getPosition = function() {
  * @observable
  * @api
  */
-_ol_Overlay_.prototype.getPositioning = function() {
+Overlay.prototype.getPositioning = function() {
   return (/** @type {ol.OverlayPositioning} */ this.get(Property.POSITIONING));
 };
 
@@ -234,7 +234,7 @@ _ol_Overlay_.prototype.getPositioning = function() {
 /**
  * @protected
  */
-_ol_Overlay_.prototype.handleElementChanged = function() {
+Overlay.prototype.handleElementChanged = function() {
   removeChildren(this.element);
   var element = this.getElement();
   if (element) {
@@ -246,7 +246,7 @@ _ol_Overlay_.prototype.handleElementChanged = function() {
 /**
  * @protected
  */
-_ol_Overlay_.prototype.handleMapChanged = function() {
+Overlay.prototype.handleMapChanged = function() {
   if (this.mapPostrenderListenerKey) {
     removeNode(this.element);
     _ol_events_.unlistenByKey(this.mapPostrenderListenerKey);
@@ -271,7 +271,7 @@ _ol_Overlay_.prototype.handleMapChanged = function() {
 /**
  * @protected
  */
-_ol_Overlay_.prototype.render = function() {
+Overlay.prototype.render = function() {
   this.updatePixelPosition();
 };
 
@@ -279,7 +279,7 @@ _ol_Overlay_.prototype.render = function() {
 /**
  * @protected
  */
-_ol_Overlay_.prototype.handleOffsetChanged = function() {
+Overlay.prototype.handleOffsetChanged = function() {
   this.updatePixelPosition();
 };
 
@@ -287,7 +287,7 @@ _ol_Overlay_.prototype.handleOffsetChanged = function() {
 /**
  * @protected
  */
-_ol_Overlay_.prototype.handlePositionChanged = function() {
+Overlay.prototype.handlePositionChanged = function() {
   this.updatePixelPosition();
   if (this.get(Property.POSITION) && this.autoPan) {
     this.panIntoView();
@@ -298,7 +298,7 @@ _ol_Overlay_.prototype.handlePositionChanged = function() {
 /**
  * @protected
  */
-_ol_Overlay_.prototype.handlePositioningChanged = function() {
+Overlay.prototype.handlePositioningChanged = function() {
   this.updatePixelPosition();
 };
 
@@ -309,7 +309,7 @@ _ol_Overlay_.prototype.handlePositioningChanged = function() {
  * @observable
  * @api
  */
-_ol_Overlay_.prototype.setElement = function(element) {
+Overlay.prototype.setElement = function(element) {
   this.set(Property.ELEMENT, element);
 };
 
@@ -320,7 +320,7 @@ _ol_Overlay_.prototype.setElement = function(element) {
  * @observable
  * @api
  */
-_ol_Overlay_.prototype.setMap = function(map) {
+Overlay.prototype.setMap = function(map) {
   this.set(Property.MAP, map);
 };
 
@@ -331,7 +331,7 @@ _ol_Overlay_.prototype.setMap = function(map) {
  * @observable
  * @api
  */
-_ol_Overlay_.prototype.setOffset = function(offset) {
+Overlay.prototype.setOffset = function(offset) {
   this.set(Property.OFFSET, offset);
 };
 
@@ -344,7 +344,7 @@ _ol_Overlay_.prototype.setOffset = function(offset) {
  * @observable
  * @api
  */
-_ol_Overlay_.prototype.setPosition = function(position) {
+Overlay.prototype.setPosition = function(position) {
   this.set(Property.POSITION, position);
 };
 
@@ -354,7 +354,7 @@ _ol_Overlay_.prototype.setPosition = function(position) {
  * (if necessary).
  * @protected
  */
-_ol_Overlay_.prototype.panIntoView = function() {
+Overlay.prototype.panIntoView = function() {
   var map = this.getMap();
 
   if (!map || !map.getTargetElement()) {
@@ -414,7 +414,7 @@ _ol_Overlay_.prototype.panIntoView = function() {
  * @return {ol.Extent} The extent.
  * @protected
  */
-_ol_Overlay_.prototype.getRect = function(element, size) {
+Overlay.prototype.getRect = function(element, size) {
   var box = element.getBoundingClientRect();
   var offsetX = box.left + window.pageXOffset;
   var offsetY = box.top + window.pageYOffset;
@@ -434,7 +434,7 @@ _ol_Overlay_.prototype.getRect = function(element, size) {
  * @observable
  * @api
  */
-_ol_Overlay_.prototype.setPositioning = function(positioning) {
+Overlay.prototype.setPositioning = function(positioning) {
   this.set(Property.POSITIONING, positioning);
 };
 
@@ -444,7 +444,7 @@ _ol_Overlay_.prototype.setPositioning = function(positioning) {
  * @param {boolean} visible Element visibility.
  * @protected
  */
-_ol_Overlay_.prototype.setVisible = function(visible) {
+Overlay.prototype.setVisible = function(visible) {
   if (this.rendered.visible !== visible) {
     this.element.style.display = visible ? '' : 'none';
     this.rendered.visible = visible;
@@ -456,7 +456,7 @@ _ol_Overlay_.prototype.setVisible = function(visible) {
  * Update pixel position.
  * @protected
  */
-_ol_Overlay_.prototype.updatePixelPosition = function() {
+Overlay.prototype.updatePixelPosition = function() {
   var map = this.getMap();
   var position = this.getPosition();
   if (!map || !map.isRendered() || !position) {
@@ -475,7 +475,7 @@ _ol_Overlay_.prototype.updatePixelPosition = function() {
  * @param {ol.Size|undefined} mapSize The map size.
  * @protected
  */
-_ol_Overlay_.prototype.updateRenderedPosition = function(pixel, mapSize) {
+Overlay.prototype.updateRenderedPosition = function(pixel, mapSize) {
   var style = this.element.style;
   var offset = this.getOffset();
 
@@ -541,8 +541,8 @@ _ol_Overlay_.prototype.updateRenderedPosition = function(pixel, mapSize) {
  * @public
  * @return {olx.OverlayOptions} overlay options
  */
-_ol_Overlay_.prototype.getOptions = function() {
+Overlay.prototype.getOptions = function() {
   return this.options;
 };
 
-export default _ol_Overlay_;
+export default Overlay;
diff --git a/src/ol/control/OverviewMap.js b/src/ol/control/OverviewMap.js
index 0a23cbf08b..0ef3be298b 100644
--- a/src/ol/control/OverviewMap.js
+++ b/src/ol/control/OverviewMap.js
@@ -8,7 +8,7 @@ import MapEventType from '../MapEventType.js';
 import _ol_MapProperty_ from '../MapProperty.js';
 import _ol_Object_ from '../Object.js';
 import ObjectEventType from '../ObjectEventType.js';
-import _ol_Overlay_ from '../Overlay.js';
+import Overlay from '../Overlay.js';
 import OverlayPositioning from '../OverlayPositioning.js';
 import _ol_ViewProperty_ from '../ViewProperty.js';
 import Control from '../control/Control.js';
@@ -140,7 +140,7 @@ var OverviewMap = function(opt_options) {
    * @type {ol.Overlay}
    * @private
    */
-  this.boxOverlay_ = new _ol_Overlay_({
+  this.boxOverlay_ = new Overlay({
     position: [0, 0],
     positioning: OverlayPositioning.BOTTOM_LEFT,
     element: box
diff --git a/test/spec/ol/map.test.js b/test/spec/ol/map.test.js
index fade1f14ac..d86c39e844 100644
--- a/test/spec/ol/map.test.js
+++ b/test/spec/ol/map.test.js
@@ -1,7 +1,7 @@
 import _ol_Feature_ from '../../../src/ol/Feature.js';
 import _ol_Map_ from '../../../src/ol/Map.js';
 import MapEvent from '../../../src/ol/MapEvent.js';
-import _ol_Overlay_ from '../../../src/ol/Overlay.js';
+import Overlay from '../../../src/ol/Overlay.js';
 import _ol_View_ from '../../../src/ol/View.js';
 import Point from '../../../src/ol/geom/Point.js';
 import _ol_has_ from '../../../src/ol/has.js';
@@ -610,7 +610,7 @@ describe('ol.Map', function() {
       });
 
       it('returns an overlay by id', function() {
-        overlay = new _ol_Overlay_({
+        overlay = new Overlay({
           id: 'foo',
           element: overlay_target,
           position: [0, 0]
@@ -620,7 +620,7 @@ describe('ol.Map', function() {
       });
 
       it('returns null when no overlay is found', function() {
-        overlay = new _ol_Overlay_({
+        overlay = new Overlay({
           id: 'foo',
           element: overlay_target,
           position: [0, 0]
@@ -630,7 +630,7 @@ describe('ol.Map', function() {
       });
 
       it('returns null after removing overlay', function() {
-        overlay = new _ol_Overlay_({
+        overlay = new Overlay({
           id: 'foo',
           element: overlay_target,
           position: [0, 0]
diff --git a/test/spec/ol/overlay.test.js b/test/spec/ol/overlay.test.js
index ec25b13555..7adf87f578 100644
--- a/test/spec/ol/overlay.test.js
+++ b/test/spec/ol/overlay.test.js
@@ -1,5 +1,5 @@
 import _ol_Map_ from '../../../src/ol/Map.js';
-import _ol_Overlay_ from '../../../src/ol/Overlay.js';
+import Overlay from '../../../src/ol/Overlay.js';
 import _ol_View_ from '../../../src/ol/View.js';
 
 
@@ -38,13 +38,13 @@ describe('ol.Overlay', function() {
   describe('constructor', function() {
 
     it('can be constructed with minimal arguments', function() {
-      var instance = new _ol_Overlay_({});
-      expect(instance).to.be.an(_ol_Overlay_);
+      var instance = new Overlay({});
+      expect(instance).to.be.an(Overlay);
     });
 
     it('can be constructed with className', function() {
-      var instance = new _ol_Overlay_({className: 'my-class'});
-      expect(instance).to.be.an(_ol_Overlay_);
+      var instance = new Overlay({className: 'my-class'});
+      expect(instance).to.be.an(Overlay);
       expect(instance.element.className).to.be('my-class');
     });
 
@@ -61,14 +61,14 @@ describe('ol.Overlay', function() {
     });
 
     it('returns the overlay identifier', function() {
-      overlay = new _ol_Overlay_({
+      overlay = new Overlay({
         element: target,
         position: [0, 0]
       });
       map.addOverlay(overlay);
       expect(overlay.getId()).to.be(undefined);
       map.removeOverlay(overlay);
-      overlay = new _ol_Overlay_({
+      overlay = new Overlay({
         id: 'foo',
         element: target,
         position: [0, 0]
@@ -90,7 +90,7 @@ describe('ol.Overlay', function() {
     });
 
     it('changes the CSS display value', function() {
-      overlay = new _ol_Overlay_({
+      overlay = new Overlay({
         element: target,
         position: [0, 0]
       });