diff --git a/src/include/taler_wire_plugin.h b/src/include/taler_wire_plugin.h
index 94ef7b328..1ee1b6b49 100644
--- a/src/include/taler_wire_plugin.h
+++ b/src/include/taler_wire_plugin.h
@@ -90,7 +90,9 @@ struct TALER_WIRE_TransferDetails
 
 /**
  * Callbacks of this type are used to serve the result of asking
- * the bank for the transaction history.
+ * the bank for the transaction history.  NOTE: this function will
+ * NOT get the list of history elements, but rather get (iteratively)
+ * called for each (parsed) history element.
  *
  * @param cls closure
  * @param ec taler error code