diff --git a/src/utils/circular_vector.hpp b/src/utils/circular_vector.hpp
index be13873..f5e283c 100644
--- a/src/utils/circular_vector.hpp
+++ b/src/utils/circular_vector.hpp
@@ -1,3 +1,4 @@
+#include <cstddef>
 #include <vector>
 
 template <class T>