diff --git a/src/exchange-lib/test_exchange_api_new.c b/src/exchange-lib/test_exchange_api_new.c
index b0819f81b..e3b383667 100644
--- a/src/exchange-lib/test_exchange_api_new.c
+++ b/src/exchange-lib/test_exchange_api_new.c
@@ -495,6 +495,11 @@ run (void *cls,
          (43,
           fakebank_url),
        "{\"items\":[{\"name\":\"ice cream\",\"value\":1}]}",
+       /**
+        * This large time unit should NEVER result in
+        * a wire transfer from the aggregation CMD below.
+        * Bug number: #5366.
+        */
        GNUNET_TIME_UNIT_FOREVER_REL,
        "EUR:5",
        MHD_HTTP_OK),