diff --git a/pyschlage/lock.py b/pyschlage/lock.py
index b411f34..826fe1d 100644
--- a/pyschlage/lock.py
+++ b/pyschlage/lock.py
@@ -137,7 +137,7 @@ def from_json(cls, auth: Auth, json: dict) -> Lock:
             name=json["name"],
             model_name=json["modelName"],
             device_type=json["devicetypeId"],
-            connected=json["connected"],
+            connected=json.get("connected", False),
             battery_level=attributes.get("batteryLevel"),
             is_locked=is_locked,
             is_jammed=is_jammed,
diff --git a/tests/test_lock.py b/tests/test_lock.py
index 989dd63..25fb4c1 100644
--- a/tests/test_lock.py
+++ b/tests/test_lock.py
@@ -1,5 +1,8 @@
+from __future__ import annotations
+
 from copy import deepcopy
 from datetime import datetime
+from typing import Any
 from unittest import mock
 
 import pytest
@@ -33,6 +36,13 @@ def test_from_json(self, mock_auth, lock_json):
             "foo-bar-uuid": User("Foo Bar", "foo@bar.xyz", "foo-bar-uuid"),
         }
 
+    def test_from_json_no_connected(
+        self, mock_auth: mock.Mock, lock_json: dict[Any, Any]
+    ) -> None:
+        lock_json.pop("connected")
+        lock = Lock.from_json(mock_auth, lock_json)
+        assert not lock.connected
+
     def test_from_json_is_jammed(self, mock_auth, lock_json):
         lock_json["attributes"]["lockState"] = 2
         lock = Lock.from_json(mock_auth, lock_json)