diff --git a/src/exchange-lib/testing_api_helpers.c b/src/exchange-lib/testing_api_helpers.c
index b3e32fc26..749e5d889 100644
--- a/src/exchange-lib/testing_api_helpers.c
+++ b/src/exchange-lib/testing_api_helpers.c
@@ -346,7 +346,9 @@ TALER_TESTING_find_pk (const struct TALER_EXCHANGE_Keys *keys,
  * @param main_cb_cls closure for @a main_cb, typically NULL.
  * @param config_file configuration file for the test-suite.
  *
- * @return FIXME: depends on what TALER_TESTING_setup returns.
+ * @return GNUNET_OK if all is okay, != GNUNET_OK otherwise.
+ *         non-GNUNET_OK codes are GNUNET_SYSERR most of the
+ *         times.
  */
 int
 TALER_TESTING_setup_with_exchange (TALER_TESTING_Main main_cb,
@@ -457,6 +459,7 @@ TALER_TESTING_setup_with_exchange (TALER_TESTING_Main main_cb,
     }
   while (0 != system (wget_cmd));
 
+  /* NOTE: this blocks.  */
   result = TALER_TESTING_setup (main_cb,
                                 main_cb_cls,
                                 config_filename,
diff --git a/src/exchange-lib/testing_api_loop.c b/src/exchange-lib/testing_api_loop.c
index ac688594e..e9197daba 100644
--- a/src/exchange-lib/testing_api_loop.c
+++ b/src/exchange-lib/testing_api_loop.c
@@ -634,7 +634,9 @@ main_wrapper_exchange_connect (void *cls)
  *        key state.. if NULL, the interpreter will run without
  *        trying to connect to the exchange first.
  *
- * @return FIXME: not sure what 'is.result' is at this stage.
+ * @return GNUNET_OK if all is okay, != GNUNET_OK otherwise.
+ *         non-GNUNET_OK codes are GNUNET_SYSERR most of the
+ *         times.
  */
 int
 TALER_TESTING_setup (TALER_TESTING_Main main_cb,