diff --git a/conformance/conformance_test.h b/conformance/conformance_test.h
index bdc7a69..00559d9 100644
--- a/conformance/conformance_test.h
+++ b/conformance/conformance_test.h
@@ -19,6 +19,7 @@
 #include <string>
 #include <vector>
 
+#include "google/protobuf/descriptor.pb.h"
 #include "google/protobuf/util/type_resolver.h"
 #include "absl/container/btree_set.h"
 #include "absl/container/flat_hash_set.h"
@@ -200,6 +201,8 @@
 
     std::unique_ptr<Message> NewTestMessage() const;
 
+    std::string GetSyntaxIdentifier() const;
+
     std::string GetTestName() const;
 
     const conformance::ConformanceRequest& GetRequest() const {