diff --git a/mainloop.cpp b/mainloop.cpp
index 4db0940..29bd378 100644
--- a/mainloop.cpp
+++ b/mainloop.cpp
@@ -28,6 +28,7 @@
 #include "targets.hpp"
 #include "thresholds.hpp"
 
+#include <cassert>
 #include <cstdlib>
 #include <functional>
 #include <iostream>