diff --git i/src/Implicit/impSurface.h w/src/Implicit/impSurface.h
index 41fab81..027587f 100644
--- i/src/Implicit/impSurface.h
+++ w/src/Implicit/impSurface.h
@@ -25,6 +25,7 @@
 #ifdef WIN32
 	#include <windows.h>
 #endif
+#include <cstddef>
 #include <vector>
 #include <GL/gl.h>