diff --git a/README_SETUP.md b/README_SETUP.md
index 801051111ad455b9b357bcfd51d936881e7dcb3a..5fe2c1e95eb583aa67108da439b2dcddaa7d59f9 100644
--- a/README_SETUP.md
+++ b/README_SETUP.md
@@ -44,6 +44,9 @@ julia> ]activate "/path/to/caosdb-julialib"
 julia> ]test
 ```
 
+Note that you must have a CaosDB client configuration (see above) with
+a valid `"default"` configuration for all tests to succeed.
+
 ## Code styling
 
 We use