diff --git a/lib/mixins/property-effects.js b/lib/mixins/property-effects.js
index e43bccc562..b36c620f87 100644
--- a/lib/mixins/property-effects.js
+++ b/lib/mixins/property-effects.js
@@ -1873,7 +1873,7 @@ export const PropertyEffects = dedupingMixin(superClass => {
      *
      * @param {string | !Array<string|number>} path Path to array.
      * @param {number} start Index from which to start removing/inserting.
-     * @param {number} deleteCount Number of items to remove.
+     * @param {number=} deleteCount Number of items to remove.
      * @param {...*} items Items to insert into array.
      * @return {Array} Array of removed items.
      * @public