diff --git a/redfish-core/lib/event_service.hpp b/redfish-core/lib/event_service.hpp
index 7359a82..6088758 100644
--- a/redfish-core/lib/event_service.hpp
+++ b/redfish-core/lib/event_service.hpp
@@ -239,8 +239,8 @@
                 {
                     if (!regPrefixes->empty() && !msgIds->empty())
                     {
-                        messages::mutualExclusiveProperties(
-                            asyncResp->res, "RegistryPrefixes", "MessageIds");
+                        messages::propertyValueConflict(
+                            asyncResp->res, "MessageIds", "RegistryPrefixes");
                         return;
                     }
                 }