diff --git a/src/ol/structs/RBush.js b/src/ol/structs/RBush.js
index ab7746db1d..3a5dfc9fc8 100644
--- a/src/ol/structs/RBush.js
+++ b/src/ol/structs/RBush.js
@@ -233,7 +233,7 @@ class RBush {
   concat(rbush) {
     this.rbush_.load(rbush.rbush_.all());
     for (const i in rbush.items_) {
-      this.items_[i | 0] = rbush.items_[i | 0];
+      this.items_[i] = rbush.items_[i];
     }
   }