diff --git a/builders/builder.py b/builders/builder.py
index bb76103..b0a0c54 100644
--- a/builders/builder.py
+++ b/builders/builder.py
@@ -90,7 +90,7 @@ class Builder(object):
 
         Return text from stdout.
         """
-        proc = Popen(cmd, stdout=PIPE, stderr=PIPE)
+        proc = Popen(cmd, stdout=PIPE, stderr=PIPE, universal_newlines=True)
         output, error = proc.communicate()
         code = proc.wait()
         if code != 0:
@@ -280,9 +280,9 @@ class Builder(object):
                 tag = '0.0.0'
                 revision = '0'
             else:
-                tag, revision = lines[-1].decode('utf-8').split()
+                tag, revision = lines[-1].split()
             output = self._bzr('log', self.branch_path, ['--line', '-r', '-1'], 'Error running bzr log')
-            revision = output.decode('utf-8').split(':')[0]
+            revision = output.split(':')[0]
             self.version = '{tag}-bzr{revision}'.format(tag=tag, revision=revision)
         # Write the version to the version file
         with open(os.path.join(self.dist_path, '.version'), 'w') as version_file:
@@ -295,7 +295,7 @@ class Builder(object):
         self._print('Copying default theme...')
         source = os.path.join(self.source_path, 'core', 'lib', 'json')
         dest = os.path.join(self.dist_path, 'core', 'lib', 'json')
-        for root, dirs, files in os.walk(source):
+        for root, _, files in os.walk(source):
             for filename in files:
                 if filename.endswith('.json'):
                     dest_path = os.path.join(dest, root[len(source) + 1:])
@@ -312,7 +312,7 @@ class Builder(object):
         self._print('Copying plugins...')
         source = os.path.join(self.source_path, 'plugins')
         dest = os.path.join(self.dist_path, 'plugins')
-        for root, dirs, files in os.walk(source):
+        for root, _, files in os.walk(source):
             for filename in files:
                 if not filename.endswith('.pyc'):
                     dest_path = os.path.join(dest, root[len(source) + 1:])
@@ -328,7 +328,7 @@ class Builder(object):
         self._print('Copying media player...')
         source = os.path.join(self.source_path, 'core', 'ui', 'media')
         dest = os.path.join(self.dist_path, 'core', 'ui', 'media')
-        for root, dirs, files in os.walk(source):
+        for root, _, files in os.walk(source):
             for filename in files:
                 if not filename.endswith('.pyc'):
                     dest_path = os.path.join(dest, root[len(source) + 1:])
@@ -373,18 +373,18 @@ class Builder(object):
         Compile the translations for Qt.
         """
         self._print('Compiling translations...')
-        files = os.listdir(self.i18n_path)
         if not os.path.exists(os.path.join(self.dist_path, 'i18n')):
             os.makedirs(os.path.join(self.dist_path, 'i18n'))
-        for file in files:
-            if file.endswith('.ts'):
-                self._print_verbose('... %s', file)
-                source_path = os.path.join(self.i18n_path, file)
-                dest_path = os.path.join(self.dist_path, 'i18n', file.replace('.ts', '.qm'))
+        for filename in os.listdir(self.i18n_path):
+            if filename.endswith('.ts'):
+                self._print_verbose('... %s', filename)
+                source_path = os.path.join(self.i18n_path, filename)
+                dest_path = os.path.join(self.dist_path, 'i18n', filename.replace('.ts', '.qm'))
                 self._run_command((self.lrelease_exe, '-compress', '-silent', source_path, '-qm', dest_path),
                                   err_msg='Error running lconvert on %s' % source_path)
         self._print('Copying Qt translation files...')
-        for filename in os.listdir(self.get_qt_translations_path()):
+        source = self.get_qt_translations_path()
+        for filename in os.listdir(source):
             if filename.startswith('qt_') and filename.endswith('.qm'):
                 self._print_verbose('... %s', filename)
                 copy(os.path.join(source, filename), os.path.join(self.dist_path, 'i18n', filename))
diff --git a/windows/config-appveyor.ini b/windows/config-appveyor.ini
index d341c77..a6f4baa 100644
--- a/windows/config-appveyor.ini
+++ b/windows/config-appveyor.ini
@@ -1,7 +1,7 @@
 [executables]
 innosetup = %(progfiles)s\Inno Setup 5\ISCC.exe
 sphinx = %(pyroot)s\Scripts\sphinx-build.exe
-pyinstaller = %(here)s\..\..\pyinstaller-develop\pyinstaller.py
+pyinstaller = %(here)s\..\..\PyInstaller-3.2\pyinstaller.py
 vcbuild = %(progfiles)s\Microsoft Visual Studio 9.0\VC\vcpackages\vcbuild.exe
 htmlhelp = %(progfiles)s\HTML Help Workshop\hhc.exe
 psvince = %(here)s\psvince.dll