diff --git a/src/cdk/drag-drop/drag-ref.ts b/src/cdk/drag-drop/drag-ref.ts
index 0a49673af560..048755e7028f 100644
--- a/src/cdk/drag-drop/drag-ref.ts
+++ b/src/cdk/drag-drop/drag-ref.ts
@@ -1103,7 +1103,10 @@ function removeElement(element: HTMLElement | null) {
 
 /** Determines whether an event is a touch event. */
 function isTouchEvent(event: MouseEvent | TouchEvent): event is TouchEvent {
-  return event.type.startsWith('touch');
+  // This function is called for every pixel that the user has dragged so we need it to be
+  // as fast as possible. Since we only bind mouse events and touch events, we can assume
+  // that if the event's name starts with `t`, it's a touch event.
+  return event.type[0] === 't';
 }
 
 /** Gets the element into which the drag preview should be inserted. */