diff --git a/src/ZGoBackend.hs b/src/ZGoBackend.hs
index 947fe42..6ca20ec 100644
--- a/src/ZGoBackend.hs
+++ b/src/ZGoBackend.hs
@@ -645,4 +645,17 @@ payOwner p d x =
                      ])
               markPaymentDone pipe db pmt
 
+expireOwners :: Pipe -> T.Text -> IO ()
+expireOwners pipe db = do
+  now <- getCurrentTime
+  _ <-
+    access
+      pipe
+      master
+      db
+      (modify
+         (select ["expiration" =: ["$lt" =: now]] "owners")
+         ["$set" =: ["paid" =: False]])
+  return ()
+
 debug = flip trace