diff --git a/src/test/storm_gtest.h b/src/test/storm_gtest.h
index 9b56f32d3..ac774dc9a 100644
--- a/src/test/storm_gtest.h
+++ b/src/test/storm_gtest.h
@@ -2,6 +2,8 @@
 
 #include "gtest/gtest.h"
 
+#include <boost/optional/optional_io.hpp>
+
 #include "storm/adapters/RationalNumberAdapter.h"
 #include "storm/utility/constants.h"
 #include "storm/utility/initialize.h"