diff -r 58695845e159 Lib/test/test_fileio.py
--- a/Lib/test/test_fileio.py	Mon Sep 28 13:35:54 2015 -0700
+++ b/Lib/test/test_fileio.py	Tue Sep 29 18:42:21 2015 +0300
@@ -377,8 +377,9 @@
                     self.assertEqual(f.writable(), True)
                     if sys.platform != "darwin" and \
                        'bsd' not in sys.platform and \
-                       not sys.platform.startswith('sunos'):
-                        # Somehow /dev/tty appears seekable on some BSDs
+                       not sys.platform.startswith('sunos') and \
+                       not sys.platform.startswith('aix'):
+                        # Somehow /dev/tty appears seekable on some systems
                         self.assertEqual(f.seekable(), False)
                     self.assertEqual(f.isatty(), True)
                     f.close()