diff --git a/include/aare/Cluster.hpp b/include/aare/Cluster.hpp
index a47edf0..e2cfe99 100644
--- a/include/aare/Cluster.hpp
+++ b/include/aare/Cluster.hpp
@@ -9,6 +9,7 @@
 #pragma once
 
 #include <algorithm>
+#include <array>
 #include <cstdint>
 #include <numeric>
 #include <type_traits>