diff --git a/src/version_check.h b/src/version_check.h
index c3370ac9..eb0d4993 100644
--- a/src/version_check.h
+++ b/src/version_check.h
@@ -18,7 +18,7 @@ a time, to avoid confusion.
 
 #ifndef OPENSCAD_SKIP_VERSION_CHECK
 
-
+#include <stddef.h> // Needed by gmp.h under OS X 10.10
 #include <gmp.h>
 // set minimum numbers here.
 #define GMPMAJOR 5