1 files changed, 15 insertions, 11 deletions
diff --git a/src/mongo/db/pipeline/document_source_change_stream_unwind_transaction.cpp b/src/mongo/db/pipeline/document_source_change_stream_unwind_transaction.cpp
index ae65c696d65..6f4877f878c 100644
--- a/src/mongo/db/pipeline/document_source_change_stream_unwind_transaction.cpp
+++ b/src/mongo/db/pipeline/document_source_change_stream_unwind_transaction.cpp
@@ -104,7 +104,7 @@ DocumentSourceChangeStreamUnwindTransaction::createFromBson(
 
 DocumentSourceChangeStreamUnwindTransaction::DocumentSourceChangeStreamUnwindTransaction(
     const BSONObj& filter, const boost::intrusive_ptr<ExpressionContext>& expCtx)
-    : DocumentSource(kStageName, expCtx) {
+    : DocumentSourceInternalChangeStreamStage(kStageName, expCtx) {
     rebuild(filter);
 }
 
@@ -126,19 +126,23 @@ StageConstraints DocumentSourceChangeStreamUnwindTransaction::constraints(
                             ChangeStreamRequirement::kChangeStreamStage);
 }
 
-Value DocumentSourceChangeStreamUnwindTransaction::serialize(
-    boost::optional<ExplainOptions::Verbosity> explain) const {
-    tassert(5467604, "expression has not been initialized", _expression);
+Value DocumentSourceChangeStreamUnwindTransaction::doSerialize(
+    const SerializationOptions& opts) const {
+    tassert(7481400, "expression has not been initialized", _expression);
 
-    if (explain) {
-        return Value(
-            DOC(DocumentSourceChangeStream::kStageName << DOC("stage"
-                                                              << "internalUnwindTransaction"_sd
-                                                              << "filter" << _filter)));
+    if (opts.verbosity) {
+        BSONObjBuilder builder;
+        builder.append("stage"_sd, "internalUnwindTransaction"_sd);
+        builder.append(DocumentSourceChangeStreamUnwindTransactionSpec::kFilterFieldName,
+                       _expression->serialize(opts));
+
+        return Value(DOC(DocumentSourceChangeStream::kStageName << builder.obj()));
     }
 
-    DocumentSourceChangeStreamUnwindTransactionSpec spec(_filter);
-    return Value(Document{{kStageName, Value(spec.toBSON())}});
+    // 'SerializationOptions' are not required here, since serialization for explain and query
+    // stats occur before this function call.
+    return Value(Document{
+        {kStageName, Value{DocumentSourceChangeStreamUnwindTransactionSpec{_filter}.toBSON()}}});
 }
 
 DepsTracker::State DocumentSourceChangeStreamUnwindTransaction::getDependencies(