diff --git a/doc/errors/index.md b/doc/errors/index.md
index cbd52e8c35..2df99e84b2 100644
--- a/doc/errors/index.md
+++ b/doc/errors/index.md
@@ -220,3 +220,7 @@ Hex color should have 3 or 6 digits.
 ### 55
 
 The `{-y}` placeholder requires a tile grid with extent.
+
+### 56
+
+`mapBrowserEvent` must originate from a pointer event.
diff --git a/src/ol/events/condition.js b/src/ol/events/condition.js
index 425ea769b9..4cc07ef5d6 100644
--- a/src/ol/events/condition.js
+++ b/src/ol/events/condition.js
@@ -2,7 +2,6 @@ goog.provide('ol.events.condition');
 
 goog.require('ol.functions');
 goog.require('ol.MapBrowserEvent.EventType');
-goog.require('ol.MapBrowserPointerEvent');
 
 
 /**
@@ -204,10 +203,9 @@ ol.events.condition.targetNotEditable = function(mapBrowserEvent) {
  * @api stable
  */
 ol.events.condition.mouseOnly = function(mapBrowserEvent) {
+  ol.assert(mapBrowserEvent.pointerEvent, 56); // mapBrowserEvent must originate from a pointer event
   // see http://www.w3.org/TR/pointerevents/#widl-PointerEvent-pointerType
-  goog.asserts.assertInstanceof(mapBrowserEvent, ol.MapBrowserPointerEvent,
-      'Requires an ol.MapBrowserPointerEvent to work.');
-  return mapBrowserEvent.pointerEvent.pointerType == 'mouse';
+  return /** @type {ol.MapBrowserEvent} */ (mapBrowserEvent).pointerEvent.pointerType == 'mouse';
 };