--- a/src/Kernel/AtomicDecomposer.cpp
+++ b/src/Kernel/AtomicDecomposer.cpp
@@ -17,6 +17,8 @@
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
+#include <ostream>
+
 #include "AtomicDecomposer.h"
 #include "logging.h"
 #include "ProgressIndicatorInterface.h"
