1 files changed, 1 insertions, 1 deletions
diff --git a/pp_sys.c b/pp_sys.c
index 54c12b30f1..501146e3c6 100644
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -3295,7 +3295,7 @@ PP(pp_fttty)
     if (GvIO(gv) && IoIFP(GvIOp(gv)))
 	fd = PerlIO_fileno(IoIFP(GvIOp(gv)));
     else if (name && isDIGIT(*name))
-        fd = atoi(name);
+        fd = grok_atou(name, NULL);
     else
 	FT_RETURNUNDEF;
     if (fd < 0) {