diff --git a/test/robustness/overlay/areal_areal/test_overlay_p_q.hpp b/test/robustness/overlay/areal_areal/test_overlay_p_q.hpp
index 6fbd38b3e..eda9bb6bf 100644
--- a/test/robustness/overlay/areal_areal/test_overlay_p_q.hpp
+++ b/test/robustness/overlay/areal_areal/test_overlay_p_q.hpp
@@ -10,6 +10,7 @@
 #define BOOST_GEOMETRY_TEST_OVERLAY_P_Q_HPP
 
 #include <fstream>
+#include <sstream>
 #include <iomanip>
 
 //#define BOOST_GEOMETRY_ROBUSTNESS_USE_DIFFERENCE