diff --git a/pageserver/src/page_service.rs b/pageserver/src/page_service.rs
index 078edc5c9f..d891b0c40a 100644
--- a/pageserver/src/page_service.rs
+++ b/pageserver/src/page_service.rs
@@ -716,7 +716,7 @@ impl PageServerHandler {
         let _enter = info_span!("get_nblocks", rel = %req.rel, req_lsn = %req.lsn).entered();
         let latest_gc_cutoff_lsn = timeline.tline.get_latest_gc_cutoff_lsn();
         let lsn = Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest, &latest_gc_cutoff_lsn)?;
-
+		assert!(req.latest);
         let n_blocks = timeline.get_rel_size(req.rel, lsn)?;
 
         Ok(PagestreamBeMessage::Nblocks(PagestreamNblocksResponse {
diff --git a/vendor/postgres b/vendor/postgres
index 9c99008445..db678091c8 160000
--- a/vendor/postgres
+++ b/vendor/postgres
@@ -1 +1 @@
-Subproject commit 9c99008445dbccd8204f188e0933def507058eac
+Subproject commit db678091c864bd7933e9b1f28adcd3b6c8545551