diff --git a/target/postfix/sender_header_filter.pcre b/target/postfix/sender_header_filter.pcre
index bc725b5e..cc0a79ab 100644
--- a/target/postfix/sender_header_filter.pcre
+++ b/target/postfix/sender_header_filter.pcre
@@ -2,7 +2,7 @@
 /^\s*Received:.*amavisd-new/        IGNORE
 /^\s*X-Originating-IP:/             IGNORE
 /^\s*X-Mailer:/                     IGNORE
-/^\s*Mime-Version: 1.0.*/           REPLACE Mime-Version: 1.0
+/^\s*Mime-Version: 1.0.*/           REPLACE MIME-Version: 1.0
 /^\s*User-Agent/                    IGNORE
 /^\s*X-Enigmail/                    IGNORE
 /^\s*X-Mailer/                      IGNORE