diff --git a/include/hibf/contrib/robin_hood.hpp b/include/hibf/contrib/robin_hood.hpp
index e14035f9..946ffc05 100644
--- a/include/hibf/contrib/robin_hood.hpp
+++ b/include/hibf/contrib/robin_hood.hpp
@@ -40,6 +40,7 @@
 #define ROBIN_HOOD_VERSION_PATCH 5  // for backwards-compatible bug fixes
 
 #include <algorithm>
+#include <cstdint>
 #include <cstdlib>
 #include <cstring>
 #include <functional>