--- a/tests/test-import-merge.t	Sun Jan 19 22:58:33 2014 -0600
+++ b/tests/test-import-merge.t	Mon Jan 20 17:09:20 2014 -0600
@@ -130,7 +130,7 @@
   $ hg ci -m3
   $ hg export 2 | head -7 > ../a.patch
   $ hg export tip > out
-  >>> apatch = open("../a.patch", "a")
+  >>> apatch = open("../a.patch", "ab")
   >>> apatch.write("".join(open("out").readlines()[7:]))
 
   $ cd ..