diff --git a/tests/test-bundle2-format.t b/tests/test-bundle2-format.t
--- a/tests/test-bundle2-format.t
+++ b/tests/test-bundle2-format.t
@@ -166,6 +166,8 @@ Create an extension to test bundle2 API
   >             file.write(chunk)
   >     except RuntimeError, exc:
   >         raise error.Abort(exc)
+  >     finally:
+  >         file.flush()
   > 
   > @command('unbundle2', [], '')
   > def cmdunbundle2(ui, repo, replypath=None):
@@ -194,9 +196,9 @@ Create an extension to test bundle2 API
   >     for rec in op.records['changegroup']:
   >         ui.write('addchangegroup return: %i\n' % rec['return'])
   >     if op.reply is not None and replypath is not None:
-  >         file = open(replypath, 'wb')
-  >         for chunk in op.reply.getchunks():
-  >             file.write(chunk)
+  >         with open(replypath, 'wb') as file:
+  >             for chunk in op.reply.getchunks():
+  >                 file.write(chunk)
   > 
   > @command('statbundle2', [], '')
   > def cmdstatbundle2(ui, repo):
diff --git a/tests/test-extension.t b/tests/test-extension.t
--- a/tests/test-extension.t
+++ b/tests/test-extension.t
@@ -7,9 +7,11 @@ Test basic extension support
   > command = cmdutil.command(cmdtable)
   > def uisetup(ui):
   >     ui.write("uisetup called\\n")
+  >     ui.flush()
   > def reposetup(ui, repo):
   >     ui.write("reposetup called for %s\\n" % os.path.basename(repo.root))
   >     ui.write("ui %s= repo.ui\\n" % (ui == repo.ui and "=" or "!"))
+  >     ui.flush()
   > @command('foo', [], 'hg foo')
   > def foo(ui, *args, **kwargs):
   >     ui.write("Foo\\n")
@@ -183,6 +185,7 @@ Check absolute/relative import of extens
   > import foo
   > def extsetup(ui):
   >     ui.write('(extroot) ', foo.func(), '\n')
+  >     ui.flush()
   > EOF
 
   $ cat > $TESTTMP/extroot/foo.py <<EOF
@@ -1077,6 +1080,7 @@ Commands handling multiple repositories 
   > from mercurial import extensions
   > def reposetup(ui, repo):
   >     ui.write('reposetup() for %s\n' % (repo.root))
+  >     ui.flush()
   > EOF
   $ hg init src
   $ echo a > src/a
diff --git a/tests/test-obsolete.t b/tests/test-obsolete.t
--- a/tests/test-obsolete.t
+++ b/tests/test-obsolete.t
@@ -935,7 +935,7 @@ Test heads computation on pending index 
   >   opts['message'] = 'Test'
   >   opts['logfile'] = None
   >   cmdutil.amend(ui, repo, commitfunc, repo['.'], {}, pats, opts)
-  >   print repo.changelog.headrevs()
+  >   ui.write('%s\n' % repo.changelog.headrevs())
   > EOF
   $ cat >> $HGRCPATH << EOF
   > [extensions]