diff --git a/pgxn/neon/pagestore_smgr.c b/pgxn/neon/pagestore_smgr.c
index cbb0e2ae6d..a5e0c402fb 100644
--- a/pgxn/neon/pagestore_smgr.c
+++ b/pgxn/neon/pagestore_smgr.c
@@ -439,6 +439,8 @@ readahead_buffer_resize(int newsize, void *extra)
 	newPState->ring_unused = newsize;
 	newPState->ring_receive = newsize;
 	newPState->ring_flush = newsize;
+	newPState->max_shard_no = MyPState->max_shard_no;
+	memcpy(newPState->shard_bitmap, MyPState->shard_bitmap, sizeof(MyPState->shard_bitmap));
 
 	/*
 	 * Copy over the prefetches.
@@ -495,7 +497,11 @@ readahead_buffer_resize(int newsize, void *extra)
 
 	for (; end >= MyPState->ring_last && end != UINT64_MAX; end -= 1)
 	{
-		prefetch_set_unused(end);
+		PrefetchRequest *slot = GetPrfSlot(end);
+		if (slot->status == PRFS_RECEIVED)
+		{
+			pfree(slot->response);
+		}
 	}
 
 	prfh_destroy(MyPState->prf_hash);
@@ -944,6 +950,9 @@ Retry:
 		Assert(entry == NULL);
 		Assert(slot == NULL);
 
+		/* There should be no buffer overflow */
+		Assert(MyPState->ring_last + readahead_buffer_size >= MyPState->ring_unused);
+
 		/*
 		 * If the prefetch queue is full, we need to make room by clearing the
 		 * oldest slot. If the oldest slot holds a buffer that was already
@@ -958,7 +967,7 @@ Retry:
 		 * a prefetch request kind of goes against the principles of
 		 * prefetching)
 		 */
-		if (MyPState->ring_last + readahead_buffer_size - 1 == MyPState->ring_unused)
+		if (MyPState->ring_last + readahead_buffer_size == MyPState->ring_unused)
 		{
 			uint64		cleanup_index = MyPState->ring_last;
 
diff --git a/test_runner/regress/test_prefetch_buffer_resize.py b/test_runner/regress/test_prefetch_buffer_resize.py
new file mode 100644
index 0000000000..7676b78b0e
--- /dev/null
+++ b/test_runner/regress/test_prefetch_buffer_resize.py
@@ -0,0 +1,40 @@
+from __future__ import annotations
+
+import random
+
+import pytest
+from fixtures.neon_fixtures import NeonEnvBuilder
+
+
+@pytest.mark.parametrize("shard_count", [None, 4])
+@pytest.mark.timeout(600)
+def test_prefetch(neon_env_builder: NeonEnvBuilder, shard_count: int | None):
+    if shard_count is not None:
+        neon_env_builder.num_pageservers = shard_count
+    env = neon_env_builder.init_start(
+        initial_tenant_shard_count=shard_count,
+    )
+    n_iter = 10
+    n_rec = 100000
+
+    endpoint = env.endpoints.create_start(
+        "main",
+        config_lines=[
+            "shared_buffers=10MB",
+        ],
+    )
+
+    cur = endpoint.connect().cursor()
+
+    cur.execute("CREATE TABLE t(pk integer, filler text default repeat('?', 200))")
+    cur.execute(f"insert into t (pk) values (generate_series(1,{n_rec}))")
+
+    cur.execute("set statement_timeout=0")
+    cur.execute("set effective_io_concurrency=20")
+    cur.execute("set max_parallel_workers_per_gather=0")
+
+    for _ in range(n_iter):
+        buf_size = random.randrange(16, 32)
+        cur.execute(f"set neon.readahead_buffer_size={buf_size}")
+        limit = random.randrange(1, n_rec)
+        cur.execute(f"select sum(pk) from (select pk from t limit {limit}) s")