diff --git a/src/calibre/translations/msgfmt.py b/src/calibre/translations/msgfmt.py
index 089f94c115..681a1d8482 100644
--- a/src/calibre/translations/msgfmt.py
+++ b/src/calibre/translations/msgfmt.py
@@ -166,7 +166,12 @@ def make(filename, outfile):
                 if not msgid:
                     # See whether there is an encoding declaration
                     p = HeaderParser()
-                    charset = p.parsestr(msgstr.decode(encoding)).get_content_charset()
+                    if sys.version_info.major > 2:
+                        charset = p.parsestr(msgstr.decode(encoding)).get_content_charset()
+                    else:
+                        charset = p.parsestr(msgstr.decode(encoding).encode('ascii', 'replace')).get_content_charset()
+                        if isinstance(charset, bytes):
+                            charset = charset.decode('ascii')
                     if charset:
                         encoding = charset
             section = ID