diff --git a/test/libdnf5/rpm/test_transaction.cpp b/test/libdnf5/rpm/test_transaction.cpp
index bf43aac79..8467ca827 100644
--- a/test/libdnf5/rpm/test_transaction.cpp
+++ b/test/libdnf5/rpm/test_transaction.cpp
@@ -39,6 +39,8 @@ using namespace libdnf5::rpm;
 using namespace libdnf5::transaction;
 
 
+namespace {
+
 class PackageDownloadCallbacks : public libdnf5::repo::DownloadCallbacks {
 public:
     int end(
@@ -76,6 +78,8 @@ class PackageDownloadCallbacks : public libdnf5::repo::DownloadCallbacks {
     int mirror_failure_cnt{0};
 };
 
+}  // namespace
+
 
 void RpmTransactionTest::test_transaction() {
     add_repo_rpm("rpm-repo1");