diff --git a/extensions/amavis_quarantine/cleanup.py b/extensions/amavis_quarantine/cleanup.py
index 3a80d4b9d..c06da7fc6 100755
--- a/extensions/amavis_quarantine/cleanup.py
+++ b/extensions/amavis_quarantine/cleanup.py
@@ -8,7 +8,7 @@ if __name__ == "__main__":
 
     main.init()
     conn = db.getconnection("amavis_quarantine")
-    max_messages_age = parameters.get_admin("amavis_quarantine", "MAX_MESSAGES_AGE")
+    max_messages_age = int(parameters.get_admin("amavis_quarantine", "MAX_MESSAGES_AGE"))
 
     print "Deleting messages older than %d days..." % max_messages_age
     db.execute(conn, """