diff --git a/src/calibre/ebooks/chardet.py b/src/calibre/ebooks/chardet.py
index 158b15fe49..f634f0a77e 100644
--- a/src/calibre/ebooks/chardet.py
+++ b/src/calibre/ebooks/chardet.py
@@ -10,16 +10,13 @@ __docformat__ = 'restructuredtext en'
 import re, codecs
 
 ENCODING_PATS = [
-                # XML declaration
-                 re.compile(r'<\?[^<>]+encoding\s*=\s*[\'"](.*?)[\'"][^<>]*>',
-                            re.IGNORECASE),
-                 # HTML 4 Pragma directive
-                 re.compile(r'''<meta\s+?[^<>]*?content\s*=\s*['"][^'"]*?charset=([-_a-z0-9]+)[^'"]*?['"][^<>]*>''',
-                            re.IGNORECASE),
-                 # HTML 5 charset
-                 re.compile(r'''<meta\s+charset=['"]([-_a-z0-9]+)['"][^<>]*>''',
-                     re.IGNORECASE),
-                 ]
+    # XML declaration
+    re.compile(r'<\?[^<>]+encoding\s*=\s*[\'"](.*?)[\'"][^<>]*>', re.IGNORECASE),
+    # HTML 4 Pragma directive
+    re.compile(r'''<meta\s+?[^<>]*?content\s*=\s*['"][^'"]*?charset=([-_a-z0-9]+)[^'"]*?['"][^<>]*>(?:\s*</meta>){0,1}''', re.IGNORECASE),
+    # HTML 5 charset
+    re.compile(r'''<meta\s+charset=['"]([-_a-z0-9]+)['"][^<>]*>(?:\s*</meta>){0,1}''', re.IGNORECASE),
+]
 ENTITY_PATTERN = re.compile(r'&(\S+?);')
 
 def strip_encoding_declarations(raw):
@@ -35,8 +32,8 @@ def substitute_entites(raw):
     from calibre import xml_entity_to_unicode
     return ENTITY_PATTERN.sub(xml_entity_to_unicode, raw)
 
-_CHARSET_ALIASES = { "macintosh" : "mac-roman",
-                        "x-sjis" : "shift-jis" }
+_CHARSET_ALIASES = {"macintosh" : "mac-roman",
+                        "x-sjis" : "shift-jis"}
 
 def detect(*args, **kwargs):
     from chardet import detect
@@ -58,8 +55,7 @@ def force_encoding(raw, verbose, assume_utf8=False):
     if not encoding:
         encoding = preferred_encoding
     encoding = encoding.lower()
-    if _CHARSET_ALIASES.has_key(encoding):
-        encoding = _CHARSET_ALIASES[encoding]
+    encoding = _CHARSET_ALIASES.get(encoding, encoding)
     if encoding == 'ascii':
         encoding = 'utf-8'
     return encoding