diff --git a/doc/changes/changes_0.3.0.md b/doc/changes/changes_0.3.0.md
index 810d185..d323609 100644
--- a/doc/changes/changes_0.3.0.md
+++ b/doc/changes/changes_0.3.0.md
@@ -8,3 +8,4 @@ This release adds integration tests for the most important calls to SaaS API.
 
 * #21: Added integration test for operation "create database"
 * #23: Added integration test for operation "add IP to whitelist"
+* #25: Fixed transitive dependencies required by generated API client
diff --git a/doc/developer_guide/developer_guide.md b/doc/developer_guide/developer_guide.md
index 4c5a7a8..2e29c4f 100644
--- a/doc/developer_guide/developer_guide.md
+++ b/doc/developer_guide/developer_guide.md
@@ -36,6 +36,26 @@ Use CLI option `--path` to read the JSON definition from a local file instead of
 "--path", "/path/to/openapi.json",
 ```
 
+### Generate file `pyproject.toml`
+
+openapi-python-client reads the JSON specification of the SaaS API and generates a python client. The generated client code requires transitive dependencies, though, which need to be added to file `pyproject.toml` to make them available for dependents of SAPIPY.
+
+The easiest way is to make openapi-python-client create a dedicated file `pyproject.toml` and copy the transitive dependencies from there to SAPIPY's file `pyproject.toml`.
+
+In order to create file `pyproject.toml`
+* In file `noxfile.py` you need to replace mode `update` by `generate`
+* Additionally in file `openapi_config.yml` you need to specify a non-existing top-level directory as `name` and a package that does not contain slashes, e.g.
+
+```yaml
+project_name_override: "generate"
+package_name_override: saas.client.openapi
+post_hooks: []
+```
+
+After generating the API,
+* Copy the dependencies from file `generate/pyproject.toml` and
+* Remove directory `generate`.
+
 ## Run Tests
 
 Executing the integration tests requires the following environment variables to be set:
diff --git a/pyproject.toml b/pyproject.toml
index 3fe57fa..b17b8af 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -25,6 +25,10 @@ python = ">=3.8.0,<4.0"
 requests = "^2.31.0"
 types-requests = "^2.31.0.6"
 ifaddr = "^0.2.0"
+# generated by openapi-python-client
+httpx = ">=0.20.0,<0.28.0"
+attrs = ">=21.3.0"
+python-dateutil = "^2.8.0"
 
 
 [build-system]