diff --git a/isatty_tcgets.go b/isatty_tcgets.go
index 31a1ca9..4e7b850 100644
--- a/isatty_tcgets.go
+++ b/isatty_tcgets.go
@@ -1,4 +1,4 @@
-// +build linux aix
+// +build linux aix zos
 // +build !appengine
 
 package isatty