diff --git a/tox.ini b/tox.ini
index 7084a80ec..8704617c5 100644
--- a/tox.ini
+++ b/tox.ini
@@ -55,7 +55,7 @@ commands = python -m testtools.run \
 # E126 continuation line over-indented for hanging indent
 # E128 continuation line under-indented for visual indent
 # E129 visually indented line with same indent as next logical line
-# E265 block comment should start with ‘# ‘
+# E265 block comment should start with '# '
 # H405 multi line docstring summary not separated with an empty line
 # TODO(marun) H404 multi line docstring should start with a summary
 # N324 contextlib.nested is deprecated