diff --git a/safekeeper/src/send_interpreted_wal.rs b/safekeeper/src/send_interpreted_wal.rs
index 308f7c92ad..820ad5a608 100644
--- a/safekeeper/src/send_interpreted_wal.rs
+++ b/safekeeper/src/send_interpreted_wal.rs
@@ -4,6 +4,7 @@ use anyhow::Context;
 use futures::StreamExt;
 use pageserver_api::shard::ShardIdentity;
 use postgres_backend::{CopyStreamHandlerEnd, PostgresBackend};
+use postgres_ffi::MAX_SEND_SIZE;
 use postgres_ffi::{get_current_timestamp, waldecoder::WalStreamDecoder};
 use pq_proto::{BeMessage, InterpretedWalRecordsBody, WalSndKeepAlive};
 use tokio::io::{AsyncRead, AsyncWrite};
@@ -38,7 +39,7 @@ impl<IO: AsyncRead + AsyncWrite + Unpin> InterpretedWalSender<'_, IO> {
         let mut wal_decoder =
             WalStreamDecoder::new(self.wal_stream_builder.start_pos(), self.pg_version);
 
-        let stream = self.wal_stream_builder.build().await?;
+        let stream = self.wal_stream_builder.build(MAX_SEND_SIZE).await?;
         let mut stream = std::pin::pin!(stream);
 
         let mut keepalive_ticker = tokio::time::interval(Duration::from_secs(1));
diff --git a/safekeeper/src/wal_reader_stream.rs b/safekeeper/src/wal_reader_stream.rs
index 9a5c0b292a..be5b29b8e1 100644
--- a/safekeeper/src/wal_reader_stream.rs
+++ b/safekeeper/src/wal_reader_stream.rs
@@ -4,7 +4,6 @@ use async_stream::try_stream;
 use bytes::Bytes;
 use futures::Stream;
 use postgres_backend::CopyStreamHandlerEnd;
-use postgres_ffi::MAX_SEND_SIZE;
 use std::time::Duration;
 use tokio::time::timeout;
 use utils::lsn::Lsn;
@@ -47,6 +46,7 @@ impl WalReaderStreamBuilder {
     /// and there's no active computes.
     pub(crate) async fn build(
         self,
+        buffer_size: usize,
     ) -> anyhow::Result<impl Stream<Item = Result<WalBytes, CopyStreamHandlerEnd>>> {
         // TODO(vlad): The code below duplicates functionality from [`crate::send_wal`].
         // We can make the raw WAL sender use this stream too and remove the duplication.
@@ -59,7 +59,7 @@ impl WalReaderStreamBuilder {
             wal_sender_guard,
         } = self;
         let mut wal_reader = tli.get_walreader(start_pos).await?;
-        let mut buffer = vec![0; MAX_SEND_SIZE];
+        let mut buffer = vec![0; buffer_size];
 
         const POLL_STATE_TIMEOUT: Duration = Duration::from_secs(1);
 
@@ -101,8 +101,8 @@ impl WalReaderStreamBuilder {
                     "nothing to send after waiting for WAL"
                 );
 
-                // try to send as much as available, capped by MAX_SEND_SIZE
-                let mut chunk_end_pos = start_pos + MAX_SEND_SIZE as u64;
+                // try to send as much as available, capped by the buffer size
+                let mut chunk_end_pos = start_pos + buffer_size as u64;
                 // if we went behind available WAL, back off
                 if chunk_end_pos >= end_pos {
                     chunk_end_pos = end_pos;