diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 4cf5b26a36..0a6c7bd83e 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -241,6 +241,11 @@
 #max_wal_size = 1GB
 #min_wal_size = 80MB

+# - Prefetching during recovery -
+
+#wal_decode_buffer_size = 512kB        # lookahead window used for prefetching