diff --git a/tests/io_test.cpp b/tests/io_test.cpp
index b5e1a9b..67a6fb8 100644
--- a/tests/io_test.cpp
+++ b/tests/io_test.cpp
@@ -1,6 +1,7 @@
 #include "assert.hpp"
 #include "client_http.hpp"
 #include "server_http.hpp"
+#include <future>
 
 using namespace std;