diff --git a/src/exchange-lib/testing_api_cmd_withdraw.c b/src/exchange-lib/testing_api_cmd_withdraw.c
index 5f3808a78..8ab5e1d2d 100644
--- a/src/exchange-lib/testing_api_cmd_withdraw.c
+++ b/src/exchange-lib/testing_api_cmd_withdraw.c
@@ -354,6 +354,8 @@ TALER_TESTING_cmd_withdraw_amount
   }
   ws->expected_response_code = expected_response_code;
   ws->exchange = exchange;
+  ws->exchange_url = MAH_path_to_url (exchange, "/");
+
   cmd.cls = ws;
   cmd.label = label;
   cmd.run = &withdraw_run;
@@ -390,7 +392,7 @@ TALER_TESTING_cmd_withdraw_denomination
   ws->pk = dk;
   ws->expected_response_code = expected_response_code;
   ws->exchange = exchange;
-  ws->exchange_url = MAH_path_to_url (ws->exchange, "/");
+  ws->exchange_url = MAH_path_to_url (exchange, "/");
 
   cmd.cls = ws;
   cmd.label = label;