diff --git a/tests/mock/sysrepo_subscription.hpp b/tests/mock/sysrepo_subscription.hpp
index 7683814..5a2ce82 100644
--- a/tests/mock/sysrepo_subscription.hpp
+++ b/tests/mock/sysrepo_subscription.hpp
@@ -29,7 +29,7 @@
 class DataSupplier {
 public:
     virtual ~DataSupplier();
-    virtual DatastoreAccess::Tree get_data(const std::string& xpath) const = 0;
+    [[nodiscard]] virtual DatastoreAccess::Tree get_data(const std::string& xpath) const = 0;
 };