--- a/tests/test-log-linerange.t	Thu Oct 19 23:16:48 2017 -0400
+++ b/tests/test-log-linerange.t	Fri Oct 20 21:29:15 2017 -0400
@@ -800,7 +800,7 @@
 Binary files work but without diff hunks filtering.
 (Checking w/ and w/o diff.git option.)
 
-  >>> open('binary', 'w').write('this\nis\na\nbinary\0')
+  >>> open('binary', 'wb').write('this\nis\na\nbinary\0')
   $ hg add binary
   $ hg ci -m 'add a binary file' --quiet
   $ hg log -f -L binary,1:2 -p