diff --git a/src/Utils/Triplet.hpp b/src/Utils/Triplet.hpp
index ba2938d9..792ff2c1 100644
--- a/src/Utils/Triplet.hpp
+++ b/src/Utils/Triplet.hpp
@@ -11,6 +11,7 @@
 #include <cassert>
 
 #include <iostream>
+#include <array>
 
 #include <boost/functional/hash.hpp>