diff --git a/core/os/os_darwin.odin b/core/os/os_darwin.odin
index 64e195422..c36823e3f 100644
--- a/core/os/os_darwin.odin
+++ b/core/os/os_darwin.odin
@@ -362,7 +362,7 @@ when  ODIN_OS == .Darwin && ODIN_ARCH == .arm64 {
 }
 
 fchmod :: proc(fd: Handle, mode: u16) -> Errno {
-	return cast(Errno)_unix_fchmod(fildes, mode)
+	return cast(Errno)_unix_fchmod(fd, mode)
 }
 
 close :: proc(fd: Handle) -> bool {
diff --git a/demo.bin b/demo.bin
new file mode 100755
index 000000000..5f8c90ed9
Binary files /dev/null and b/demo.bin differ