diff --git a/netlib/http/message.py b/netlib/http/message.py
index b84f45c5f..0b64d4a60 100644
--- a/netlib/http/message.py
+++ b/netlib/http/message.py
@@ -278,7 +278,7 @@ class Message(basetypes.Serializable):
             self.content, replacements = re.subn(
                 pattern, repl, self.content, flags=flags, count=count
             )
-        replacements += self.headers.replace(pattern, repl, flags)
+        replacements += self.headers.replace(pattern, repl, flags=flags, count=count)
         return replacements
 
     # Legacy