diff --git a/.cirrus.star b/.cirrus.star
new file mode 100644
index 0000000000..d2d6ceca20
--- /dev/null
+++ b/.cirrus.star
@@ -0,0 +1,63 @@
+"""Additional CI configuration, using the starlark language. See
+https://cirrus-ci.org/guide/programming-tasks/#introduction-into-starlark
+
+See also the starlark specification at
+https://github.com/bazelbuild/starlark/blob/master/spec.md
+
+See also .cirrus.yml and src/tools/ci/README
+"""
+
+load("cirrus", "env", "fs")
+
+
+def main():
+    """The main function is executed by cirrus-ci after loading .cirrus.yml and can
+    extend the CI definition further.
+
+    As documented in .cirrus.yml, the final CI configuration is composed of
+
+    1) the contents of .cirrus.yml
+
+    2) if defined, the contents of the file referenced by the, repository
+       level, REPO_CI_CONFIG_GIT_URL variable (see
+       https://cirrus-ci.org/guide/programming-tasks/#fs for the accepted
+       format)
+
+    3) .cirrus.tasks.yml
+    """
+
+    output = ""
+
+    # 1) is evaluated implicitly
+
+    # Add 2)
+    repo_config_url = env.get("REPO_CI_CONFIG_GIT_URL")
+    if repo_config_url != None:
+        print("loading additional configuration from \"{}\"".format(repo_config_url))
+        output += config_from(repo_config_url)
+    else:
+        output += "\n# REPO_CI_CONFIG_URL was not set\n"
+
+    # Add 3)
+    output += config_from(".cirrus.tasks.yml")
+
+    return output
+
+
+def config_from(config_src):
+    """return contents of config file `config_src`, surrounded by markers
+    indicating start / end of the the included file
+    """
+
+    config_contents = fs.read(config_src)
+    config_fmt = """
+
+###
+# contents of config file `{0}` start here
+###
+{1}
+###
+# contents of config file `{0}` end here
+###
+"""
+    return config_fmt.format(config_src, config_contents)
diff --git a/.cirrus.yml b/.cirrus.tasks.yml
similarity index 100%
rename from .cirrus.yml
rename to .cirrus.tasks.yml