diff --git a/django/utils/cache.py b/django/utils/cache.py
index 2753d86949..2494d7839e 100644
--- a/django/utils/cache.py
+++ b/django/utils/cache.py
@@ -42,9 +42,9 @@ def patch_cache_control(response, **kwargs):
     def dictitem(s):
         t = s.split('=',1)
         if len(t) > 1:
-            return (t[0].lower().replace('-', '_'), t[1])
+            return (t[0].lower(), t[1])
         else:
-            return (t[0].lower().replace('-', '_'), True)
+            return (t[0].lower(), True)
 
     def dictvalue(t):
         if t[1] is True: