diff --git a/src/calibre/ebooks/rtf2xml/ParseRtf.py b/src/calibre/ebooks/rtf2xml/ParseRtf.py
index 2dacc0c49d..5b008df615 100755
--- a/src/calibre/ebooks/rtf2xml/ParseRtf.py
+++ b/src/calibre/ebooks/rtf2xml/ParseRtf.py
@@ -233,7 +233,7 @@ class ParseRtf:
                 bug_handler = RtfInvalidCodeException,
                     )
             check_encoding_obj.check_encoding(self.__file)
-            sys.stderr.write('File "%s" does not appear to be RTF.\n' % self.__file)
+            sys.stderr.write('File "%s" does not appear to be RTF.\n' % self.__file if isinstance(self.__file, str) else self.__file.encode('utf-8'))
             raise InvalidRtfException, msg
         delete_info_obj = delete_info.DeleteInfo(
             in_file = self.__temp_file,
diff --git a/src/calibre/ebooks/rtf2xml/check_encoding.py b/src/calibre/ebooks/rtf2xml/check_encoding.py
index d2bd4f8ce1..f6810e4909 100755
--- a/src/calibre/ebooks/rtf2xml/check_encoding.py
+++ b/src/calibre/ebooks/rtf2xml/check_encoding.py
@@ -23,7 +23,10 @@ class CheckEncoding:
             try:
                 line.decode(encoding)
             except UnicodeError:
-                self.__get_position_error(line, encoding, line_num)
+                if len(line) < 1000:
+                    self.__get_position_error(line, encoding, line_num)
+                else:
+                    sys.stderr.write('line: %d has bad encoding\n'%line_num)
 if __name__ == '__main__':
     check_encoding_obj = CheckEncoding()
     check_encoding_obj.check_encoding(sys.argv[1])