diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index 5792cd14a0..d3ec137051 100644
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -1474,6 +1474,8 @@ ReorderBufferCommit(ReorderBuffer *rb, TransactionId xid,
 					 * use as a normal record. It'll be cleaned up at the end
 					 * of INSERT processing.
 					 */
+					if (specinsert == NULL)
+						elog(ERROR, "invalid ordering of speculative insertion changes");
 					Assert(specinsert->data.tp.oldtuple == NULL);
 					change = specinsert;
 					change->action = REORDER_BUFFER_CHANGE_INSERT;