1 files changed, 2 insertions, 0 deletions

diff --git a/src/fileio.c b/src/fileio.c
index 697e2281d6d..0f550733223 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -3275,5 +3275,7 @@ and FILENAME is handled by HANDLER, then HANDLER is called like this:\n\
   defsubr (&Sread_file_name_internal);
   defsubr (&Sread_file_name);
 
+#ifdef unix
   defsubr (&Sunix_sync);
+#endif
 }