diff --git a/redfish-core/lib/systems.hpp b/redfish-core/lib/systems.hpp
index 2e88367..cae0fe8 100644
--- a/redfish-core/lib/systems.hpp
+++ b/redfish-core/lib/systems.hpp
@@ -617,6 +617,12 @@
                     aResp->res.jsonValue["PowerState"] = "On";
                     aResp->res.jsonValue["Status"]["State"] = "Enabled";
                 }
+                else if (*s == "xyz.openbmc_project.State.Host.HostState."
+                               "DiagnosticMode")
+                {
+                    aResp->res.jsonValue["PowerState"] = "On";
+                    aResp->res.jsonValue["Status"]["State"] = "InTest";
+                }
                 else
                 {
                     aResp->res.jsonValue["PowerState"] = "Off";