diff --git a/sros2/sros2/api/__init__.py b/sros2/sros2/api/__init__.py
index a3f4d7f1..2f01e74b 100644
--- a/sros2/sros2/api/__init__.py
+++ b/sros2/sros2/api/__init__.py
@@ -14,7 +14,9 @@
 
 from collections import namedtuple
 import datetime
+import errno
 import os
+import pathlib
 import shutil
 import sys
 
@@ -324,9 +326,13 @@ def create_key(keystore_path, identity):
 
 
 def list_keys(keystore_path):
-    for name in os.listdir(keystore_path):
-        if os.path.isdir(os.path.join(keystore_path, name)):
-            print(name)
+    if not os.path.isdir(keystore_path):
+        raise FileNotFoundError(
+            errno.ENOENT, os.strerror(errno.ENOENT), keystore_path)
+    p = pathlib.Path(keystore_path)
+    key_file_paths = sorted(p.glob('**/key.pem'))
+    for key_file_path in key_file_paths:
+        print('/{}'.format(key_file_path.parent.relative_to(keystore_path).as_posix()))
     return True
 
 
diff --git a/sros2/test/sros2/commands/security/verbs/test_list_keys.py b/sros2/test/sros2/commands/security/verbs/test_list_keys.py
index a38f6622..efaff95c 100644
--- a/sros2/test/sros2/commands/security/verbs/test_list_keys.py
+++ b/sros2/test/sros2/commands/security/verbs/test_list_keys.py
@@ -20,17 +20,19 @@
 
 
 def test_list_keys(capsys):
+    key_names = ['/test_node', '/test_namespace/test_node', '/sky/is/the/limit']
     with tempfile.TemporaryDirectory() as keystore_dir:
         with capsys.disabled():
             # First, create the keystore
             assert create_keystore(keystore_dir)
 
             # Now using that keystore, create a keypair
-            assert create_key(keystore_dir, '/test_node')
+            for key in key_names:
+                assert create_key(keystore_dir, key)
 
         # Now verify that the key we just created is included in the list
         assert cli.main(argv=['security', 'list_keys', keystore_dir]) == 0
-        assert capsys.readouterr().out.strip() == 'test_node'
+        assert capsys.readouterr().out.strip() == '\n'.join(sorted(key_names))
 
 
 def test_list_keys_no_keys(capsys):