diff --git a/termsize.go b/termsize.go
index 829e477..c23417c 100644
--- a/termsize.go
+++ b/termsize.go
@@ -1,4 +1,4 @@
-// +build !windows,!plan9,!appengine,!wasm
+// +build !windows,!plan9,!appengine,!wasm,!aix
 
 package flags
 
diff --git a/termsize_nosysioctl.go b/termsize_nosysioctl.go
index c1ff186..e809607 100644
--- a/termsize_nosysioctl.go
+++ b/termsize_nosysioctl.go
@@ -1,4 +1,4 @@
-// +build plan9 appengine wasm
+// +build plan9 appengine wasm aix
 
 package flags