diff --git a/Lib/csv.py b/Lib/csv.py
index b2aaf5fd9fa91e..8e35e998bc0a10 100644
--- a/Lib/csv.py
+++ b/Lib/csv.py
@@ -331,7 +331,7 @@ def _guess_quote_and_delimiter(self, data, delimiters):
         # if we see an extra quote between delimiters, we've got a
         # double quoted format
         dq_regexp = re.compile(
-                               r"((%(delim)s)|^)\W*%(quote)s[^%(delim)s\n]*%(quote)s[^%(delim)s\n]*%(quote)s\W*((%(delim)s)|$)" % \
+                               r"((%(delim)s)|^)\W*%(quote)s(?>[^%(delim)s\n]*)%(quote)s[^%(delim)s\n]*%(quote)s\W*((%(delim)s)|$)" % \
                                {'delim':re.escape(delim), 'quote':quotechar}, re.MULTILINE)