diff --git a/Lib/cgi.py b/Lib/cgi.py
index b4c620a..e7cd778 100755
--- a/Lib/cgi.py
+++ b/Lib/cgi.py
@@ -293,7 +293,7 @@
     while s[:1] == ';':
         s = s[1:]
         end = s.find(';')
-        while end > 0 and s.count('"', 0, end) % 2:
+        while end > 0 and (s.count('"', 0, end) - s.count('\\"', 0, end)) % 2:
             end = s.find(';', end + 1)
         if end < 0:
             end = len(s)