diff --git a/src/backend/replication/logical/decode.c b/src/backend/replication/logical/decode.c
index 5315d93af0..582b6a2b96 100644
--- a/src/backend/replication/logical/decode.c
+++ b/src/backend/replication/logical/decode.c
@@ -361,10 +361,12 @@ DecodeHeap2Op(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
 	/*
 	 * If we don't have snapshot or we are just fast-forwarding, there is no
-	 * point in decoding changes.
+	 * point in decoding changes (except NEW_CID assignments, because we need
+	 * to have subxid applied to xid in that case.)
 	 */
-	if (SnapBuildCurrentState(builder) < SNAPBUILD_FULL_SNAPSHOT ||
-		ctx->fast_forward)
+	if ((info != XLOG_HEAP2_NEW_CID) &&
+		(SnapBuildCurrentState(builder) < SNAPBUILD_FULL_SNAPSHOT ||
+		 ctx->fast_forward))
 		return;
 
 	switch (info)
diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index 8ce28ad629..6faba6077e 100644
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -778,9 +778,6 @@ ReorderBufferAssignChild(ReorderBuffer *rb, TransactionId xid,
 	txn = ReorderBufferTXNByXid(rb, xid, true, &new_top, lsn, true);
 	subtxn = ReorderBufferTXNByXid(rb, subxid, true, &new_sub, lsn, false);
 
-	if (new_top && !new_sub)
-		elog(ERROR, "subtransaction logged without previous top-level txn record");
-
 	if (!new_sub)
 	{
 		if (subtxn->is_known_as_subxact)
diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c
index 0bd1d0f954..326f5b7809 100644
--- a/src/backend/replication/logical/snapbuild.c
+++ b/src/backend/replication/logical/snapbuild.c
@@ -772,6 +772,13 @@ SnapBuildProcessNewCid(SnapBuild *builder, TransactionId xid,
 {
 	CommandId	cid;
 
+	/*
+	 * In rare cases, it is possible that we're seeing a subtransaction
+	 * for the first time.  Record it in that case.
+	 */
+	if (xlrec->top_xid != xid)
+		ReorderBufferAssignChild(builder->reorder, xlrec->top_xid, xid, lsn);
+
 	/*
 	 * we only log new_cid's if a catalog tuple was modified, so mark the
 	 * transaction as containing catalog modifications