diff --git a/changelog/upgrade-notes.md b/changelog/upgrade-notes.md
index d543af1dff..c26a8ae1b3 100644
--- a/changelog/upgrade-notes.md
+++ b/changelog/upgrade-notes.md
@@ -16,6 +16,7 @@ A number of internal types have been renamed.  This will not affect those who us
  * rename `ol.DeviceOrientationProperty` to `ol.DeviceOrientation.Property`
  * rename `ol.GeolocationProperty` to `ol.Geolocation.Property`
  * rename `ol.OverlayProperty` to `ol.Overlay.Property`
+ * rename `ol.OverlayPositioning` to `ol.Overlay.Positioning`
 
 ### v3.18.0
 
diff --git a/externs/olx.js b/externs/olx.js
index 36d31e7ba9..2efc516b79 100644
--- a/externs/olx.js
+++ b/externs/olx.js
@@ -308,7 +308,7 @@ olx.MapOptions.prototype.view;
  *     element: (Element|undefined),
  *     offset: (Array.<number>|undefined),
  *     position: (ol.Coordinate|undefined),
- *     positioning: (ol.OverlayPositioning|string|undefined),
+ *     positioning: (ol.Overlay.Positioning|string|undefined),
  *     stopEvent: (boolean|undefined),
  *     insertFirst: (boolean|undefined),
  *     autoPan: (boolean|undefined),
@@ -359,7 +359,7 @@ olx.OverlayOptions.prototype.position;
  * property. Possible values are `'bottom-left'`, `'bottom-center'`,
  * `'bottom-right'`, `'center-left'`, `'center-center'`, `'center-right'`,
  * `'top-left'`, `'top-center'`, and `'top-right'`. Default is `'top-left'`.
- * @type {ol.OverlayPositioning|string|undefined}
+ * @type {ol.Overlay.Positioning|string|undefined}
  * @api stable
  */
 olx.OverlayOptions.prototype.positioning;
diff --git a/src/ol/control/overviewmap.js b/src/ol/control/overviewmap.js
index 290e66bd0b..731d773c94 100644
--- a/src/ol/control/overviewmap.js
+++ b/src/ol/control/overviewmap.js
@@ -8,7 +8,6 @@ goog.require('ol.MapProperty');
 goog.require('ol.Object');
 goog.require('ol.ObjectEventType');
 goog.require('ol.Overlay');
-goog.require('ol.OverlayPositioning');
 goog.require('ol.View');
 goog.require('ol.control.Control');
 goog.require('ol.coordinate');
@@ -124,7 +123,7 @@ ol.control.OverviewMap = function(opt_options) {
    */
   this.boxOverlay_ = new ol.Overlay({
     position: [0, 0],
-    positioning: ol.OverlayPositioning.BOTTOM_LEFT,
+    positioning: ol.Overlay.Positioning.BOTTOM_LEFT,
     element: box
   });
   this.ovmap_.addOverlay(this.boxOverlay_);
diff --git a/src/ol/overlay.js b/src/ol/overlay.js
index f6355e5a65..588c2b8ec5 100644
--- a/src/ol/overlay.js
+++ b/src/ol/overlay.js
@@ -1,5 +1,4 @@
 goog.provide('ol.Overlay');
-goog.provide('ol.OverlayPositioning');
 
 goog.require('ol');
 goog.require('ol.events');
@@ -10,25 +9,6 @@ goog.require('ol.dom');
 goog.require('ol.extent');
 
 
-/**
- * Overlay position: `'bottom-left'`, `'bottom-center'`,  `'bottom-right'`,
- * `'center-left'`, `'center-center'`, `'center-right'`, `'top-left'`,
- * `'top-center'`, `'top-right'`
- * @enum {string}
- */
-ol.OverlayPositioning = {
-  BOTTOM_LEFT: 'bottom-left',
-  BOTTOM_CENTER: 'bottom-center',
-  BOTTOM_RIGHT: 'bottom-right',
-  CENTER_LEFT: 'center-left',
-  CENTER_CENTER: 'center-center',
-  CENTER_RIGHT: 'center-right',
-  TOP_LEFT: 'top-left',
-  TOP_CENTER: 'top-center',
-  TOP_RIGHT: 'top-right'
-};
-
-
 /**
  * @classdesc
  * An element to be displayed over the map and attached to a single map
@@ -150,8 +130,8 @@ ol.Overlay = function(options) {
   this.setOffset(options.offset !== undefined ? options.offset : [0, 0]);
 
   this.setPositioning(options.positioning !== undefined ?
-      /** @type {ol.OverlayPositioning} */ (options.positioning) :
-      ol.OverlayPositioning.TOP_LEFT);
+      /** @type {ol.Overlay.Positioning} */ (options.positioning) :
+      ol.Overlay.Positioning.TOP_LEFT);
 
   if (options.position !== undefined) {
     this.setPosition(options.position);
@@ -222,13 +202,13 @@ ol.Overlay.prototype.getPosition = function() {
 
 /**
  * Get the current positioning of this overlay.
- * @return {ol.OverlayPositioning} How the overlay is positioned
+ * @return {ol.Overlay.Positioning} How the overlay is positioned
  *     relative to its point on the map.
  * @observable
  * @api stable
  */
 ol.Overlay.prototype.getPositioning = function() {
-  return /** @type {ol.OverlayPositioning} */ (
+  return /** @type {ol.Overlay.Positioning} */ (
       this.get(ol.Overlay.Property.POSITIONING));
 };
 
@@ -432,7 +412,7 @@ ol.Overlay.prototype.getRect_ = function(element, size) {
 
 /**
  * Set the positioning for this overlay.
- * @param {ol.OverlayPositioning} positioning how the overlay is
+ * @param {ol.Overlay.Positioning} positioning how the overlay is
  *     positioned relative to its point on the map.
  * @observable
  * @api stable
@@ -488,9 +468,9 @@ ol.Overlay.prototype.updateRenderedPosition = function(pixel, mapSize) {
 
   var offsetX = offset[0];
   var offsetY = offset[1];
-  if (positioning == ol.OverlayPositioning.BOTTOM_RIGHT ||
-      positioning == ol.OverlayPositioning.CENTER_RIGHT ||
-      positioning == ol.OverlayPositioning.TOP_RIGHT) {
+  if (positioning == ol.Overlay.Positioning.BOTTOM_RIGHT ||
+      positioning == ol.Overlay.Positioning.CENTER_RIGHT ||
+      positioning == ol.Overlay.Positioning.TOP_RIGHT) {
     if (this.rendered_.left_ !== '') {
       this.rendered_.left_ = style.left = '';
     }
@@ -502,9 +482,9 @@ ol.Overlay.prototype.updateRenderedPosition = function(pixel, mapSize) {
     if (this.rendered_.right_ !== '') {
       this.rendered_.right_ = style.right = '';
     }
-    if (positioning == ol.OverlayPositioning.BOTTOM_CENTER ||
-        positioning == ol.OverlayPositioning.CENTER_CENTER ||
-        positioning == ol.OverlayPositioning.TOP_CENTER) {
+    if (positioning == ol.Overlay.Positioning.BOTTOM_CENTER ||
+        positioning == ol.Overlay.Positioning.CENTER_CENTER ||
+        positioning == ol.Overlay.Positioning.TOP_CENTER) {
       offsetX -= this.element_.offsetWidth / 2;
     }
     var left = Math.round(pixel[0] + offsetX) + 'px';
@@ -512,9 +492,9 @@ ol.Overlay.prototype.updateRenderedPosition = function(pixel, mapSize) {
       this.rendered_.left_ = style.left = left;
     }
   }
-  if (positioning == ol.OverlayPositioning.BOTTOM_LEFT ||
-      positioning == ol.OverlayPositioning.BOTTOM_CENTER ||
-      positioning == ol.OverlayPositioning.BOTTOM_RIGHT) {
+  if (positioning == ol.Overlay.Positioning.BOTTOM_LEFT ||
+      positioning == ol.Overlay.Positioning.BOTTOM_CENTER ||
+      positioning == ol.Overlay.Positioning.BOTTOM_RIGHT) {
     if (this.rendered_.top_ !== '') {
       this.rendered_.top_ = style.top = '';
     }
@@ -526,9 +506,9 @@ ol.Overlay.prototype.updateRenderedPosition = function(pixel, mapSize) {
     if (this.rendered_.bottom_ !== '') {
       this.rendered_.bottom_ = style.bottom = '';
     }
-    if (positioning == ol.OverlayPositioning.CENTER_LEFT ||
-        positioning == ol.OverlayPositioning.CENTER_CENTER ||
-        positioning == ol.OverlayPositioning.CENTER_RIGHT) {
+    if (positioning == ol.Overlay.Positioning.CENTER_LEFT ||
+        positioning == ol.Overlay.Positioning.CENTER_CENTER ||
+        positioning == ol.Overlay.Positioning.CENTER_RIGHT) {
       offsetY -= this.element_.offsetHeight / 2;
     }
     var top = Math.round(pixel[1] + offsetY) + 'px';
@@ -541,6 +521,25 @@ ol.Overlay.prototype.updateRenderedPosition = function(pixel, mapSize) {
 };
 
 
+/**
+ * Overlay position: `'bottom-left'`, `'bottom-center'`,  `'bottom-right'`,
+ * `'center-left'`, `'center-center'`, `'center-right'`, `'top-left'`,
+ * `'top-center'`, `'top-right'`
+ * @enum {string}
+ */
+ol.Overlay.Positioning = {
+  BOTTOM_LEFT: 'bottom-left',
+  BOTTOM_CENTER: 'bottom-center',
+  BOTTOM_RIGHT: 'bottom-right',
+  CENTER_LEFT: 'center-left',
+  CENTER_CENTER: 'center-center',
+  CENTER_RIGHT: 'center-right',
+  TOP_LEFT: 'top-left',
+  TOP_CENTER: 'top-center',
+  TOP_RIGHT: 'top-right'
+};
+
+
 /**
  * @enum {string}
  */