diff --git a/.github/workflows/benchmarking.yml b/.github/workflows/benchmarking.yml
index a5cf4b4694..860e5d72b6 100644
--- a/.github/workflows/benchmarking.yml
+++ b/.github/workflows/benchmarking.yml
@@ -232,7 +232,8 @@ jobs:
       if: matrix.platform == 'neon-captest-prefetch'
       run: |
         psql ${BENCHMARK_CONNSTR} -c "ALTER DATABASE neondb SET enable_seqscan_prefetch=on"
-        psql ${BENCHMARK_CONNSTR} -c "ALTER DATABASE neondb SET seqscan_prefetch_buffers=10"
+        psql ${BENCHMARK_CONNSTR} -c "ALTER DATABASE neondb SET effective_io_concurrency=32"
+        psql ${BENCHMARK_CONNSTR} -c "ALTER DATABASE neondb SET maintenance_io_concurrency=32"
       env:
         BENCHMARK_CONNSTR: ${{ steps.set-up-connstr.outputs.connstr }}
 
diff --git a/pgxn/neon/libpagestore.c b/pgxn/neon/libpagestore.c
index ae8275168d..1aba2e1ede 100644
--- a/pgxn/neon/libpagestore.c
+++ b/pgxn/neon/libpagestore.c
@@ -464,12 +464,12 @@ pg_init_libpagestore(void)
 							NULL, NULL, NULL);
 	DefineCustomIntVariable("neon.readahead_buffer_size",
 							"number of prefetches to buffer",
-							"This buffer is used to store prefetched data; so "
-							"it is important that this buffer is at least as "
-							"large as the configured value of all tablespaces' "
-							"effective_io_concurrency and maintenance_io_concurrency, "
-							"your sessions' values of these, and the value for "
-							"seqscan_prefetch_buffers.",
+							"This buffer is used to hold and manage prefetched "
+							"data; so it is important that this buffer is at "
+							"least as large as the configured value of all "
+							"tablespaces' effective_io_concurrency and "
+							"maintenance_io_concurrency, and your sessions' "
+							"values for these settings.",
 							&readahead_buffer_size,
 							128, 16, 1024,
 							PGC_USERSET,
diff --git a/vendor/postgres-v14 b/vendor/postgres-v14
index da50d99db5..06edb5af61 160000
--- a/vendor/postgres-v14
+++ b/vendor/postgres-v14
@@ -1 +1 @@
-Subproject commit da50d99db54848f7a3e910f920aaad7dc6915d36
+Subproject commit 06edb5af6180f99ee1bd6903bae2898d2ea128ef
diff --git a/vendor/postgres-v15 b/vendor/postgres-v15
index 780c3f8e35..edf4c161dd 160000
--- a/vendor/postgres-v15
+++ b/vendor/postgres-v15
@@ -1 +1 @@
-Subproject commit 780c3f8e3524c2e32a2e28884c7b647fcebf71d7
+Subproject commit edf4c161dd0182d22c28297e841ca253bc1b8ee4