Patch #1540470, for OpenBSD 4.0.  Backport candidate for 2.[34].
diff --git a/Lib/test/test_fcntl.py b/Lib/test/test_fcntl.py
index 58a57b5..2d800b2 100755
--- a/Lib/test/test_fcntl.py
+++ b/Lib/test/test_fcntl.py
@@ -25,7 +25,7 @@
                     'freebsd2', 'freebsd3', 'freebsd4', 'freebsd5',
                     'freebsd6', 'freebsd7',
                     'bsdos2', 'bsdos3', 'bsdos4',
-                    'openbsd', 'openbsd2', 'openbsd3'):
+                    'openbsd', 'openbsd2', 'openbsd3', 'openbsd4'):
     if struct.calcsize('l') == 8:
         off_t = 'l'
         pid_t = 'i'