diff --git b/test/util.py a/test/util.py
new file mode 100644
index 0000000..0551d06
--- /dev/null
+++ a/test/util.py
@@ -0,0 +1,18 @@
+from click.testing import CliRunner
+from ykman.cli.__main__ import cli
+import os
+
+
+PKG_DIR = os.path.dirname(os.path.abspath(__file__))
+
+
+def open_file(*relative_path):
+    return open(os.path.join(PKG_DIR, 'files', *relative_path), 'rb')
+
+
+def ykman_cli(*argv, **kwargs):
+    runner = CliRunner()
+    result = runner.invoke(cli, list(argv), obj={}, **kwargs)
+    if result.exit_code != 0:
+        raise result.exception
+    return result.output
