diff --git a/ballerina/tests/test.bal b/ballerina/tests/test.bal
index 35bb3c3..43cfebf 100644
--- a/ballerina/tests/test.bal
+++ b/ballerina/tests/test.bal
@@ -18,9 +18,9 @@ import ballerina/http;
 import ballerina/oauth2;
 import ballerina/test;
 
-configurable string clientId = ?;
-configurable string clientSecret = ?;
-configurable string refreshToken = ?;
+configurable string clientId = "clientId";
+configurable string clientSecret ="clientSecret";
+configurable string refreshToken = "refreshToken";
 
 OAuth2RefreshTokenGrantConfig auth = {
     clientId,