diff --git a/python/python/python.conf b/python/python/python.conf
index 5214120a0..c50ad412f 100644
--- a/python/python/python.conf
+++ b/python/python/python.conf
@@ -57,4 +57,6 @@ if atstage cross; then
 	var_append configcache ' ' "ac_cv_buggy_getaddrinfo=no"
 	# on a running system we have /dev/ptmx
 	var_append configcache ' ' "ac_cv_file__dev_ptmx=yes"
+	# no /dev/ptc because it is AIX specific
+	var_append configcache ' ' "ac_cv_file__dev_ptc=no"
 fi