diff --git a/server/conf/sieve_filter.master b/server/conf/sieve_filter.master
index 16a39ec1801259d3acd74d6c36be6b1eb431787a..fd216d3d6401bf2e81f35b7239041daabbfd6054 100644
--- a/server/conf/sieve_filter.master
+++ b/server/conf/sieve_filter.master
@@ -7,7 +7,7 @@ require ["fileinto", "mailbox", "regex", "date", "relational", "vacation", "imap
 
 <tmpl_if name="move_junk" op="==" value="y">
 # Move spam to spam folder
-if anyof (header :contains "X-Spam-Flag" "YES", header :contains ["X-Spam", "X-Spam-Status"] "Yes") {
+if anyof (header :is ["X-Spam", "X-Spam-Flag"] "Yes", header :matches "X-Spam-Status" "Yes, *") {
   fileinto :create "Junk";
   # Stop here so that we do not reply on spams
   stop;
@@ -33,7 +33,7 @@ require ["fileinto", "mailbox", "regex", "date", "relational", "vacation", "imap
 
 <tmpl_if name="move_junk" op="==" value="a">
 # Move spam to spam folder
-if anyof (header :contains "X-Spam-Flag" "YES", header :contains ["X-Spam", "X-Spam-Status"] "Yes") {
+if anyof (header :is ["X-Spam", "X-Spam-Flag"] "Yes", header :matches "X-Spam-Status" "Yes, *") {
   fileinto :create "Junk";
   # Stop here so that we do not reply on spams
   stop;
@@ -46,7 +46,7 @@ if anyof (header :contains "X-Spam-Flag" "YES", header :contains ["X-Spam", "X-S
 #################################################################
 
 # Move spam to spam folder
-if anyof (header :contains "X-Spam-Flag" "YES", header :contains ["X-Spam", "X-Spam-Status"] "Yes") {
+if anyof (header :is ["X-Spam", "X-Spam-Flag"] "Yes", header :matches "X-Spam-Status" "Yes, *") {
   # Stop here so that we do not reply on spams
   stop;
 }