diff --git a/debugging/vov-bug-finder/kp_view_of_views_bug_finder.cpp b/debugging/vov-bug-finder/kp_view_of_views_bug_finder.cpp
index 48d2eaae4..9f4cec2d5 100644
--- a/debugging/vov-bug-finder/kp_view_of_views_bug_finder.cpp
+++ b/debugging/vov-bug-finder/kp_view_of_views_bug_finder.cpp
@@ -37,7 +37,8 @@ class {
  public:
   std::mutex mutex;
   uint64_t push(std::string s) {
-    map_.emplace_hint(map_.end(), count_, std::move(s));
+    auto it = map_.emplace_hint(map_.end(), count_, std::move(s));
+    assert(++it == map_.end());
     return count_++;
   }
   void pop(uint64_t x) {