diff --git a/src/ol/MapBrowserEventHandler.js b/src/ol/MapBrowserEventHandler.js
index e19b74e55e..18f5899701 100644
--- a/src/ol/MapBrowserEventHandler.js
+++ b/src/ol/MapBrowserEventHandler.js
@@ -275,7 +275,8 @@ class MapBrowserEventHandler extends EventTarget {
    * @private
    */
   handleTouchMove_(event) {
-    if (this.originalPointerMoveEvent_.defaultPrevented) {
+    // In some environments (such as iOS 12), this handler can get called once before the `originalPointerMoveEvent_` is initialized. This prevents crashes in those situations (but may not work correctly if `originalPointerMoveEvent_` lags behind the current event?).
+    if (this.originalPointerMoveEvent_ && this.originalPointerMoveEvent_.defaultPrevented) {
       event.preventDefault();
     }
   }