diff --git a/munkres.hpp b/munkres.hpp
index 694aff1..ac2ecca 100644
--- a/munkres.hpp
+++ b/munkres.hpp
@@ -12,6 +12,7 @@
 #include <limits>
 #include <vector>
 #include <algorithm>
+#include <cstdint>
 
 namespace detail
 {