diff --git a/irr/include/vector3d.h b/irr/include/vector3d.h
index a69f17e16..72a41f665 100644
--- a/irr/include/vector3d.h
+++ b/irr/include/vector3d.h
@@ -7,6 +7,7 @@
 #include "irrMath.h"
 
 #include <functional>
+#include <ostream>
 
 namespace irr
 {