diff --git a/qutebrowser/browser/network/qutescheme.py b/qutebrowser/browser/network/qutescheme.py
index 9daea70e4..639f7cb8c 100644
--- a/qutebrowser/browser/network/qutescheme.py
+++ b/qutebrowser/browser/network/qutescheme.py
@@ -213,7 +213,8 @@ def qute_help(win_id, request):
     if urlpath.endswith('.png'):
         return utils.read_file(path, binary=True)
     else:
-        return utils.read_file(path).encode('UTF-8', errors='xmlcharrefreplace')
+        data = utils.read_file(path)
+        return data.encode('UTF-8', errors='xmlcharrefreplace')
 
 
 @add_handler('settings')
diff --git a/scripts/asciidoc2html.py b/scripts/asciidoc2html.py
index b8f5d59e1..9bf1b1d87 100755
--- a/scripts/asciidoc2html.py
+++ b/scripts/asciidoc2html.py
@@ -87,7 +87,6 @@ class AsciiDoc:
             files.append((src, dst))
 
         # patch image links to use local copy
-        modified_files = []
         replacements = [
             ("http://qutebrowser.org/img/cheatsheet-big.png",
                 "qute://help/img/cheatsheet-big.png"),