diff --git a/lang/cem/libcc/gen/isatty.c b/lang/cem/libcc/gen/isatty.c
index 4fa9cad35..aeee7ff7a 100644
--- a/lang/cem/libcc/gen/isatty.c
+++ b/lang/cem/libcc/gen/isatty.c
@@ -6,6 +6,6 @@ isatty(f)
 	   where gtty is an ioctl(..., TCGETA, ...)
 	*/
 
-	if (gtty(f, &ttyb) < 0) return 0;
+	if (gtty(f, &buf) < 0) return 0;
 	return 1;
 }