diff --git a/upgrades/2018-upgrade-to-2.23.sql b/upgrades/2018-upgrade-to-2.23.sql
deleted file mode 100644
index c686009a..00000000
--- a/upgrades/2018-upgrade-to-2.23.sql
+++ /dev/null
@@ -1,2 +0,0 @@
-/* Issue #457 - clean up zero dates just for tidyness */
-UPDATE _person SET status_last_changed = NULL where CAST(status_last_changed AS CHAR(20)) = '0000-00-00 00:00:00' ;