diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index 26d252bd87..bd643d96c6 100644
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -3602,13 +3602,13 @@ ReorderBufferCheckMemoryLimit(ReorderBuffer *rb)
 			rb->size > 0))
 	{
 		/*
-		 * Pick the largest transaction (or subtransaction) and evict it from
-		 * memory by streaming, if possible.  Otherwise, spill to disk.
+		 * Pick the largest top-level (streamable) transaction evict it
+		 * from memory by streaming, if possible.  Otherwise, spill to
+		 * disk.
 		 */
 		if (ReorderBufferCanStartStreaming(rb) &&
 			(txn = ReorderBufferLargestStreamableTopTXN(rb)) != NULL)
 		{
-			/* we know there has to be one, because the size is not zero */
 			Assert(txn && rbtxn_is_toptxn(txn));
 			Assert(txn->total_size > 0);
 			Assert(rb->size >= txn->total_size);