diff --git a/src/engine/cmdStream.cpp b/src/engine/cmdStream.cpp
index 210af399..7b1a6033 100644
--- a/src/engine/cmdStream.cpp
+++ b/src/engine/cmdStream.cpp
@@ -17,6 +17,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#define _USE_MATH_DEFINES
 #include "cmdStream.h"
 #include "dispatch.h"
 #include "engine.h"