diff --git a/tests/functional/Voltha_ScaleFunctionalTests.robot b/tests/functional/Voltha_ScaleFunctionalTests.robot
index 9ea1d93..6858aa5 100644
--- a/tests/functional/Voltha_ScaleFunctionalTests.robot
+++ b/tests/functional/Voltha_ScaleFunctionalTests.robot
@@ -213,7 +213,7 @@
 
 Delete Device and Verify
     [Documentation]    Disable -> Delete devices via voltctl and verify its removed
-    ${rc}    ${output}=    Run and Return Rc and Output    ${VOLTCTL_CONFIG}; voltctl device disable ${olt_device_id}
+    ${rc}    ${output}=    Run and Return Rc and Output    voltctl -c ${VOLTCTL_CONFIG} device disable ${olt_device_id}
     Should Be Equal As Integers    ${rc}    0
     Wait Until Keyword Succeeds    ${timeout}    5s    Validate OLT Device    DISABLED    UNKNOWN    REACHABLE
     ...    ${olt_serial_number}