--- sdevel/cctypeinfo.c
+++ sdevel/cctypeinfo.c
@@ -18,6 +18,8 @@
#else
# include <netinet/in.h>
# define SIZET_FMT "z"
-# define HAVE_LOFF_T 1
+# if defined(_GNU_SOURCE)
+# define HAVE_LOFF_T 1
+# endif
#endif