diff --git a/src/exchange-lib/testing_api_cmd_wire.c b/src/exchange-lib/testing_api_cmd_wire.c
index c403f6a4b..52fe2ebb8 100644
--- a/src/exchange-lib/testing_api_cmd_wire.c
+++ b/src/exchange-lib/testing_api_cmd_wire.c
@@ -170,7 +170,7 @@ wire_run (void *cls,
           struct TALER_TESTING_Interpreter *is)
 {
   struct WireState *ws = cls;
-  ws->is = i;
+  ws->is = is;
   ws->wh = TALER_EXCHANGE_wire (ws->exchange,
                                 &wire_cb,
                                 ws);