diff --git a/docs/docs/developer/testing.md b/docs/docs/developer/testing.md
index fecb58f592..ad64ba015c 100644
--- a/docs/docs/developer/testing.md
+++ b/docs/docs/developer/testing.md
@@ -4,7 +4,8 @@
 
 ### Unit tests
 
-Unit are run by calling `npm run test` from the `server` directory.
+Unit are run by calling `npm run test` from the `server/` directory.
+You need to run `npm install` (in `server/`) before _once_.
 
 ### End to end tests
 
@@ -14,6 +15,11 @@ The e2e tests can be run by first starting up a test production environment via:
 make e2e
 ```
 
+Before you can run the tests, you need to run the following commands _once_:
+
+- `npm install` (in `e2e/`)
+- `make open-api` (in the project root `/`)
+
 Once the test environment is running, the e2e tests can be run via:
 
 ```bash