diff --git a/control/zone.hpp b/control/zone.hpp
index 11cfc65..d01e972 100644
--- a/control/zone.hpp
+++ b/control/zone.hpp
@@ -1,4 +1,5 @@
 #pragma once
+#include <cassert>
 #include <chrono>
 #include <vector>
 #include <cassert>