diff --git a/dovecot/files/filter_junk.sieve b/dovecot/files/filter_junk.sieve
index 3e4d1ddbba0a71eb79e220744381a61a254edac6..bf4276e09a7df0013a744017c276b390f33fd04e 100644
--- a/dovecot/files/filter_junk.sieve
+++ b/dovecot/files/filter_junk.sieve
@@ -1,4 +1,4 @@
-require "fileinto";
+require ["fileinto", "mailbox"];
 
 if header :contains "X-Spam-Flag" "YES" {
  fileinto :create "Junk";