diff --git a/src/you_get/util/strings.py b/src/you_get/util/strings.py
index 7e74f35e..a81cc15c 100644
--- a/src/you_get/util/strings.py
+++ b/src/you_get/util/strings.py
@@ -1,25 +1,25 @@
 try:
-  # py 3.4
-  from html import unescape as unescape_html
+    # py 3.4
+    from html import unescape as unescape_html
 except ImportError:
-  import re
-  from html.entities import entitydefs
+    import re
+    from html.entities import entitydefs
 
-  def unescape_html(string):
-    '''HTML entity decode'''
-    string = re.sub(r'&#[^;]+;', _sharp2uni, string)
-    string = re.sub(r'&[^;]+;', lambda m: entitydefs[m.group(0)[1:-1]], string)
-    return string
+    def unescape_html(string):
+        '''HTML entity decode'''
+        string = re.sub(r'&#[^;]+;', _sharp2uni, string)
+        string = re.sub(r'&[^;]+;', lambda m: entitydefs[m.group(0)[1:-1]], string)
+        return string
 
-  def _sharp2uni(m):
-    '''&#...; ==> unicode'''
-    s = m.group(0)[2:].rstrip(';；')
-    if s.startswith('x'):
-      return chr(int('0'+s, 16))
-    else:
-      return chr(int(s))
+    def _sharp2uni(m):
+        '''&#...; ==> unicode'''
+        s = m.group(0)[2:].rstrip(';；')
+        if s.startswith('x'):
+            return chr(int('0'+s, 16))
+        else:
+            return chr(int(s))
 
 from .fs import legitimize
 
 def get_filename(htmlstring):
-  return legitimize(unescape_html(htmlstring))
+    return legitimize(unescape_html(htmlstring))