diff --git a/sc2/src/sc2code/libs/sound/mixsdl/mixer.c b/sc2/src/sc2code/libs/sound/mixsdl/mixer.c
index 329fe7a4c..3b2d5b69c 100644
--- a/sc2/src/sc2code/libs/sound/mixsdl/mixer.c
+++ b/sc2/src/sc2code/libs/sound/mixsdl/mixer.c
@@ -20,6 +20,7 @@
  */
 
 #include "starcon.h"
+#include <math.h>
 #include "mixer.h"
 #include "libs/misc.h"
 #include "SDL.h"