diff --git a/redfish/dmtf_tools/test_redfishtool_certificate.robot b/redfish/dmtf_tools/test_redfishtool_certificate.robot
index 3a38313..586a766 100644
--- a/redfish/dmtf_tools/test_redfishtool_certificate.robot
+++ b/redfish/dmtf_tools/test_redfishtool_certificate.robot
@@ -381,7 +381,7 @@
     ${payload}=  Set Variable  '${string}'
 
     ${expected_resp}=  Set Variable If  '${expected_status}' == 'ok'  ${HTTP_OK}
-    ...  '${expected_status}' == 'error'  ${HTTP_NOT_FOUND}, ${HTTP_INTERNAL_SERVER_ERROR}
+    ...  '${expected_status}' == 'error'  ${HTTP_NOT_FOUND},${HTTP_INTERNAL_SERVER_ERROR}
 
     ${response}=  Redfishtool Post
     ...  ${payload}  /redfish/v1/CertificateService/Actions/CertificateService.ReplaceCertificate