1 files changed, 3 insertions, 2 deletions
diff --git a/newlib/libc/sys/arc/isatty.c b/newlib/libc/sys/arc/isatty.c
index 3c64647a9..fe64209b9 100644
--- a/newlib/libc/sys/arc/isatty.c
+++ b/newlib/libc/sys/arc/isatty.c
@@ -3,13 +3,14 @@
 /* Dumb implementation so programs will at least run.  */
 
 #include <sys/stat.h>
+#include <reent.h>
 
 int
-isatty (int fd)
+_isatty_r (struct _reent *ptr, int fd)
 {
   struct stat buf;
 
-  if (fstat (fd, &buf) < 0)
+  if (_fstat_r (ptr, fd, &buf) < 0)
     return 0;
   if (S_ISCHR (buf.st_mode))
     return 1;