diff --git a/test/stressIterators.cxx b/test/stressIterators.cxx
index cc734563dda6ba7434912585175d0c2bdca810e8..2c60319b91d39fbe9d31405308a939d28452d9aa 100644
--- a/test/stressIterators.cxx
+++ b/test/stressIterators.cxx
@@ -22,6 +22,7 @@
 #include <algorithm>
 #include <sstream>
 #include <stdexcept>
+#include <functional>
 // ROOT
 #include "TList.h"
 #include "TObjString.h"