diff --git vcglib/wrap/ply/plystuff.h vcglib/wrap/ply/plystuff.h
index 3e41e63..4af9508 100644
--- vcglib/wrap/ply/plystuff.h
+++ vcglib/wrap/ply/plystuff.h
@@ -75,6 +75,7 @@ using namespace vcg;
 #define pb_close  _close
 #define DIR_SEP "\\"
 #else
+#include <unistd.h>
 #define pb_mkdir(n)  mkdir(n,0755)
 #define pb_access access
 #define pb_stat   stat