diff --git a/redfish-core/lib/certificate_service.hpp b/redfish-core/lib/certificate_service.hpp
index f26909b..a316cc5 100644
--- a/redfish-core/lib/certificate_service.hpp
+++ b/redfish-core/lib/certificate_service.hpp
@@ -123,14 +123,14 @@
     {
         BMCWEB_LOG_ERROR << "Required parameters are missing";
         messages::internalError(asyncResp->res);
-        return std::string();
+        return {};
     }
 
     if (*certificateType != "PEM")
     {
         messages::propertyValueNotInList(asyncResp->res, *certificateType,
                                          "CertificateType");
-        return std::string();
+        return {};
     }
 
     return certificate;