diff --git a/src/core/environment/uniform_grid_environment.cc b/src/core/environment/uniform_grid_environment.cc
index 2f6fc7edf..1dbf5dde6 100644
--- a/src/core/environment/uniform_grid_environment.cc
+++ b/src/core/environment/uniform_grid_environment.cc
@@ -98,8 +98,6 @@ struct AgentHandleIterator : public Iterator<AgentHandle> {
   AgentHandle Next() override {
     while (box_it.IsAtEnd()) {
       box_index++;
-      assert(box_index < sorted_boxes.size() &&
-             "box_index out of bounds. This should not happen.");
       box_it = sorted_boxes[box_index]->begin(grid_);
     }
     auto ret = *box_it;