diff --git a/src/ol/ImageCanvas.js b/src/ol/ImageCanvas.js
index c848a55077..55374de5a3 100644
--- a/src/ol/ImageCanvas.js
+++ b/src/ol/ImageCanvas.js
@@ -94,7 +94,7 @@ ImageCanvas.prototype.load = function() {
 
 
 /**
- * @inheritDoc
+ * @return {HTMLCanvasElement} Canvas element.
  */
 ImageCanvas.prototype.getImage = function() {
   return this.canvas_;
diff --git a/src/ol/dom.js b/src/ol/dom.js
index ee58409535..52c46ada47 100644
--- a/src/ol/dom.js
+++ b/src/ol/dom.js
@@ -10,14 +10,14 @@
  * @return {CanvasRenderingContext2D} The context.
  */
 export function createCanvasContext2D(opt_width, opt_height) {
-  const canvas = document.createElement('CANVAS');
+  const canvas = /** @type {HTMLCanvasElement} */ (document.createElement('CANVAS'));
   if (opt_width) {
     canvas.width = opt_width;
   }
   if (opt_height) {
     canvas.height = opt_height;
   }
-  return canvas.getContext('2d');
+  return /** @type {CanvasRenderingContext2D} */ (canvas.getContext('2d'));
 }
 
 
diff --git a/src/ol/pointer/MsSource.js b/src/ol/pointer/MsSource.js
index 09f45d9903..2e1b7618c5 100644
--- a/src/ol/pointer/MsSource.js
+++ b/src/ol/pointer/MsSource.js
@@ -54,7 +54,7 @@ const MsSource = function(dispatcher) {
 
   /**
    * @const
-   * @type {!Object.<string, Event|Object>}
+   * @type {!Object.<string, MSPointerEvent|Object>}
    */
   this.pointerMap = dispatcher.pointerMap;
 };
@@ -79,7 +79,7 @@ const POINTER_TYPES = [
  * for the fake pointer event.
  *
  * @private
- * @param {Event} inEvent The in event.
+ * @param {MSPointerEvent} inEvent The in event.
  * @return {Object} The copied event.
  */
 MsSource.prototype.prepareEvent_ = function(inEvent) {
@@ -105,7 +105,7 @@ MsSource.prototype.cleanup = function(pointerId) {
 /**
  * Handler for `msPointerDown`.
  *
- * @param {Event} inEvent The in event.
+ * @param {MSPointerEvent} inEvent The in event.
  */
 MsSource.prototype.msPointerDown = function(inEvent) {
   this.pointerMap[inEvent.pointerId.toString()] = inEvent;
@@ -117,7 +117,7 @@ MsSource.prototype.msPointerDown = function(inEvent) {
 /**
  * Handler for `msPointerMove`.
  *
- * @param {Event} inEvent The in event.
+ * @param {MSPointerEvent} inEvent The in event.
  */
 MsSource.prototype.msPointerMove = function(inEvent) {
   const e = this.prepareEvent_(inEvent);
@@ -128,7 +128,7 @@ MsSource.prototype.msPointerMove = function(inEvent) {
 /**
  * Handler for `msPointerUp`.
  *
- * @param {Event} inEvent The in event.
+ * @param {MSPointerEvent} inEvent The in event.
  */
 MsSource.prototype.msPointerUp = function(inEvent) {
   const e = this.prepareEvent_(inEvent);
@@ -140,7 +140,7 @@ MsSource.prototype.msPointerUp = function(inEvent) {
 /**
  * Handler for `msPointerOut`.
  *
- * @param {Event} inEvent The in event.
+ * @param {MSPointerEvent} inEvent The in event.
  */
 MsSource.prototype.msPointerOut = function(inEvent) {
   const e = this.prepareEvent_(inEvent);
@@ -151,7 +151,7 @@ MsSource.prototype.msPointerOut = function(inEvent) {
 /**
  * Handler for `msPointerOver`.
  *
- * @param {Event} inEvent The in event.
+ * @param {MSPointerEvent} inEvent The in event.
  */
 MsSource.prototype.msPointerOver = function(inEvent) {
   const e = this.prepareEvent_(inEvent);
@@ -162,7 +162,7 @@ MsSource.prototype.msPointerOver = function(inEvent) {
 /**
  * Handler for `msPointerCancel`.
  *
- * @param {Event} inEvent The in event.
+ * @param {MSPointerEvent} inEvent The in event.
  */
 MsSource.prototype.msPointerCancel = function(inEvent) {
   const e = this.prepareEvent_(inEvent);
@@ -174,7 +174,7 @@ MsSource.prototype.msPointerCancel = function(inEvent) {
 /**
  * Handler for `msLostPointerCapture`.
  *
- * @param {Event} inEvent The in event.
+ * @param {MSPointerEvent} inEvent The in event.
  */
 MsSource.prototype.msLostPointerCapture = function(inEvent) {
   const e = this.dispatcher.makeEvent('lostpointercapture',
@@ -186,7 +186,7 @@ MsSource.prototype.msLostPointerCapture = function(inEvent) {
 /**
  * Handler for `msGotPointerCapture`.
  *
- * @param {Event} inEvent The in event.
+ * @param {MSPointerEvent} inEvent The in event.
  */
 MsSource.prototype.msGotPointerCapture = function(inEvent) {
   const e = this.dispatcher.makeEvent('gotpointercapture',
diff --git a/src/ol/renderer/canvas/VectorLayer.js b/src/ol/renderer/canvas/VectorLayer.js
index bd3af95e42..da780638ff 100644
--- a/src/ol/renderer/canvas/VectorLayer.js
+++ b/src/ol/renderer/canvas/VectorLayer.js
@@ -29,7 +29,7 @@ const CanvasVectorLayerRenderer = function(vectorLayer) {
    * Declutter tree.
    * @private
    */
-  this.declutterTree_ = vectorLayer.getDeclutter() ? rbush(9) : null;
+  this.declutterTree_ = vectorLayer.getDeclutter() ? rbush(9, undefined) : null;
 
   /**
    * @private
diff --git a/src/ol/renderer/canvas/VectorTileLayer.js b/src/ol/renderer/canvas/VectorTileLayer.js
index 9d903f45b7..e4a7035691 100644
--- a/src/ol/renderer/canvas/VectorTileLayer.js
+++ b/src/ol/renderer/canvas/VectorTileLayer.js
@@ -66,7 +66,7 @@ const CanvasVectorTileLayerRenderer = function(layer) {
    * Declutter tree.
    * @private
    */
-  this.declutterTree_ = layer.getDeclutter() ? rbush(9) : null;
+  this.declutterTree_ = layer.getDeclutter() ? rbush(9, undefined) : null;
 
   /**
    * @private
diff --git a/src/ol/source/Tile.js b/src/ol/source/Tile.js
index 79c3e598f7..c2f53d1b0a 100644
--- a/src/ol/source/Tile.js
+++ b/src/ol/source/Tile.js
@@ -107,7 +107,7 @@ TileSource.prototype.canExpireCache = function() {
 
 /**
  * @param {module:ol/proj/Projection} projection Projection.
- * @param {Object.<string, module:ol/TileRange>} usedTiles Used tiles.
+ * @param {!Object.<string, module:ol/TileRange>} usedTiles Used tiles.
  */
 TileSource.prototype.expireCache = function(projection, usedTiles) {
   const tileCache = this.getTileCacheForProjection(projection);
diff --git a/src/ol/structs/RBush.js b/src/ol/structs/RBush.js
index ae57c7b486..dceecb0712 100644
--- a/src/ol/structs/RBush.js
+++ b/src/ol/structs/RBush.js
@@ -29,7 +29,7 @@ const RBush = function(opt_maxEntries) {
   /**
    * @private
    */
-  this.rbush_ = rbush(opt_maxEntries);
+  this.rbush_ = rbush(opt_maxEntries, undefined);
 
   /**
    * A mapping between the objects added to this rbush wrapper