diff --git a/src/fslsurface/fslsurface_structs.h b/src/fslsurface/fslsurface_structs.h
index 119a94f..0454b97 100644
--- a/src/fslsurface/fslsurface_structs.h
+++ b/src/fslsurface/fslsurface_structs.h
@@ -71,7 +71,7 @@
 #else
 #include <OpenGL/gl.h>
 #endif
-//#include <cmath>
+#include <cmath>
 
 namespace fslsurface_name{
 	enum MarchingCubesMode {EQUAL_TO, GREATER_THAN, GREATER_THAN_EQUAL_TO};
