diff --git a/certidude/cli.py b/certidude/cli.py
index 07d5899..f9c41e9 100755
--- a/certidude/cli.py
+++ b/certidude/cli.py
@@ -469,7 +469,10 @@ def certidude_setup_authority(parent, country, state, locality, organization, or
     if not re.match(r"^[_a-zA-Z0-9]+$", slug):
         raise click.ClickException("CA name can contain only alphanumeric and '_' characters")
 
-    click.echo("CA configuration files are saved to: {}".format(os.path.abspath(slug)))
+    if os.path.lexists(directory):
+        raise click.ClickException("Output directory {} already exists.".format(directory))
+
+    click.echo("CA configuration files are saved to: {}".format(directory))
 
     click.echo("Generating 4096-bit RSA key...")
 
diff --git a/tests/test_cli.py b/tests/test_cli.py
index bc74ea1..6037fa2 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -41,3 +41,11 @@ def test_cli_setup_authority_invalid_name():
 
         result = runner.invoke(cli, ['setup', 'authority', '""'])
         assert result.exception
+
+def test_cli_setup_authority_overwrite():
+    with runner.isolated_filesystem():
+        result = runner.invoke(cli, ['setup', 'authority', 'foo'])
+        assert not result.exception
+
+        result = runner.invoke(cli, ['setup', 'authority', 'foo'])
+        assert result.exception