diff --git a/cpp/src/arrow/flight/sql/server_session_middleware_internals_test.cc b/cpp/src/arrow/flight/sql/server_session_middleware_internals_test.cc
index 93f162e280318..4d6aa673022a7 100644
--- a/cpp/src/arrow/flight/sql/server_session_middleware_internals_test.cc
+++ b/cpp/src/arrow/flight/sql/server_session_middleware_internals_test.cc
@@ -29,7 +29,7 @@ namespace sql {
 class ServerSessionMiddlewareFactoryPrivate : public ServerSessionMiddlewareFactory {
  public:
   using ServerSessionMiddlewareFactory::ParseCookieString;
-}
+};
 
 TEST(ServerSessionMiddleware, Dummy) {
   ASSERT_EQ(1, 1);