diff --git a/config/modules/rprh.sql b/config/modules/rprh.sql
index 456b1a4..c4accb9 100644
--- a/config/modules/rprh.sql
+++ b/config/modules/rprh.sql
@@ -53,4 +53,8 @@ SELECT
   NWPDAT AS nwpdat,
   NWPTIM AS nwptim
 FROM LGDAT.RPRH
+-- NWPDAT is 0001-01-01 until the batch posts, so the watermark branch alone can
+-- never see an in-flight batch -- it only appears once posting stamps a real
+-- date. Only 4 rows are unposted, so the whole set comes over every run.
 WHERE NWPDAT >= DATE('{stamp}')
+   OR RTRIM(NWPOST) <> 'Y'