diff --git a/test/flat_tree_test.cpp b/test/flat_tree_test.cpp
index 67f2558..6be6f3a 100644
--- a/test/flat_tree_test.cpp
+++ b/test/flat_tree_test.cpp
@@ -11,6 +11,7 @@
 #include <boost/container/small_vector.hpp>
 #include <boost/container/stable_vector.hpp>
 #include <boost/container/static_vector.hpp>
+#include <boost/container/detail/pair.hpp>
 
 #include <iostream>