diff --git a/tests/components/roku/fixtures/roku3-diagnostics-data.json b/tests/components/roku/fixtures/roku3-diagnostics-data.json
deleted file mode 100644
index a3084b010c9..00000000000
--- a/tests/components/roku/fixtures/roku3-diagnostics-data.json
+++ /dev/null
@@ -1,86 +0,0 @@
-{
-  "app": {
-    "app_id": null,
-    "name": "Roku",
-    "screensaver": false,
-    "version": null
-  },
-  "apps": [
-    {
-      "app_id": "11",
-      "name": "Roku Channel Store",
-      "screensaver": false,
-      "version": null
-    },
-    {
-      "app_id": "12",
-      "name": "Netflix",
-      "screensaver": false,
-      "version": null
-    },
-    {
-      "app_id": "13",
-      "name": "Amazon Video on Demand",
-      "screensaver": false,
-      "version": null
-    },
-    {
-      "app_id": "14",
-      "name": "MLB.TV®",
-      "screensaver": false,
-      "version": null
-    },
-    {
-      "app_id": "26",
-      "name": "Free FrameChannel Service",
-      "screensaver": false,
-      "version": null
-    },
-    {
-      "app_id": "27",
-      "name": "Mediafly",
-      "screensaver": false,
-      "version": null
-    },
-    {
-      "app_id": "28",
-      "name": "Pandora",
-      "screensaver": false,
-      "version": null
-    },
-    {
-      "app_id": "74519",
-      "name": "Pluto TV - It's Free TV",
-      "screensaver": false,
-      "version": "5.2.0"
-    }
-  ],
-  "channel": null,
-  "channels": [],
-  "info": {
-    "brand": "Roku",
-    "device_location": null,
-    "device_type": "box",
-    "ethernet_mac": "b0:a7:37:96:4d:fa",
-    "ethernet_support": true,
-    "headphones_connected": false,
-    "model_name": "Roku 3",
-    "model_number": "4200X",
-    "name": "My Roku 3",
-    "network_name": null,
-    "network_type": "ethernet",
-    "serial_number": "1GU48T017973",
-    "supports_airplay": false,
-    "supports_find_remote": false,
-    "supports_private_listening": false,
-    "supports_wake_on_wlan": false,
-    "version": "7.5.0",
-    "wifi_mac": "b0:a7:37:96:4d:fb"
-  },
-  "media": null,
-  "state": {
-    "at": "2022-01-23T21:05:03.154737",
-    "available": true,
-    "standby": false
-  }
-}
diff --git a/tests/components/roku/snapshots/test_diagnostics.ambr b/tests/components/roku/snapshots/test_diagnostics.ambr
new file mode 100644
index 00000000000..1742d1f7ee0
--- /dev/null
+++ b/tests/components/roku/snapshots/test_diagnostics.ambr
@@ -0,0 +1,98 @@
+# serializer version: 1
+# name: test_diagnostics
+  dict({
+    'data': dict({
+      'app': dict({
+        'app_id': None,
+        'name': 'Roku',
+        'screensaver': False,
+        'version': None,
+      }),
+      'apps': list([
+        dict({
+          'app_id': '11',
+          'name': 'Roku Channel Store',
+          'screensaver': False,
+          'version': None,
+        }),
+        dict({
+          'app_id': '12',
+          'name': 'Netflix',
+          'screensaver': False,
+          'version': None,
+        }),
+        dict({
+          'app_id': '13',
+          'name': 'Amazon Video on Demand',
+          'screensaver': False,
+          'version': None,
+        }),
+        dict({
+          'app_id': '14',
+          'name': 'MLB.TV®',
+          'screensaver': False,
+          'version': None,
+        }),
+        dict({
+          'app_id': '26',
+          'name': 'Free FrameChannel Service',
+          'screensaver': False,
+          'version': None,
+        }),
+        dict({
+          'app_id': '27',
+          'name': 'Mediafly',
+          'screensaver': False,
+          'version': None,
+        }),
+        dict({
+          'app_id': '28',
+          'name': 'Pandora',
+          'screensaver': False,
+          'version': None,
+        }),
+        dict({
+          'app_id': '74519',
+          'name': "Pluto TV - It's Free TV",
+          'screensaver': False,
+          'version': '5.2.0',
+        }),
+      ]),
+      'channel': None,
+      'channels': list([
+      ]),
+      'info': dict({
+        'brand': 'Roku',
+        'device_location': None,
+        'device_type': 'box',
+        'ethernet_mac': 'b0:a7:37:96:4d:fa',
+        'ethernet_support': True,
+        'headphones_connected': False,
+        'model_name': 'Roku 3',
+        'model_number': '4200X',
+        'name': 'My Roku 3',
+        'network_name': None,
+        'network_type': 'ethernet',
+        'serial_number': '1GU48T017973',
+        'supports_airplay': False,
+        'supports_find_remote': False,
+        'supports_private_listening': False,
+        'supports_wake_on_wlan': False,
+        'version': '7.5.0',
+        'wifi_mac': 'b0:a7:37:96:4d:fb',
+      }),
+      'media': None,
+      'state': dict({
+        'at': '2023-08-15T17:00:00+00:00',
+        'available': True,
+        'standby': False,
+      }),
+    }),
+    'entry': dict({
+      'data': dict({
+        'host': '192.168.1.160',
+      }),
+      'unique_id': '1GU48T017973',
+    }),
+  })
+# ---
diff --git a/tests/components/roku/test_diagnostics.py b/tests/components/roku/test_diagnostics.py
index 860d0424624..708e6d3f5e3 100644
--- a/tests/components/roku/test_diagnostics.py
+++ b/tests/components/roku/test_diagnostics.py
@@ -1,9 +1,11 @@
 """Tests for the diagnostics data provided by the Roku integration."""
-import json
+from rokuecp import Device as RokuDevice
+from syrupy import SnapshotAssertion
 
 from homeassistant.core import HomeAssistant
+from homeassistant.util import dt as dt_util
 
-from tests.common import MockConfigEntry, load_fixture
+from tests.common import MockConfigEntry
 from tests.components.diagnostics import get_diagnostics_for_config_entry
 from tests.typing import ClientSessionGenerator
 
@@ -11,27 +13,14 @@ from tests.typing import ClientSessionGenerator
 async def test_diagnostics(
     hass: HomeAssistant,
     hass_client: ClientSessionGenerator,
+    mock_device: RokuDevice,
     init_integration: MockConfigEntry,
+    snapshot: SnapshotAssertion,
 ) -> None:
     """Test diagnostics for config entry."""
-    diagnostics_data = json.loads(load_fixture("roku/roku3-diagnostics-data.json"))
+    mock_device.state.at = dt_util.parse_datetime("2023-08-15 17:00:00-00:00")
 
-    result = await get_diagnostics_for_config_entry(hass, hass_client, init_integration)
-
-    assert isinstance(result, dict)
-    assert isinstance(result["entry"], dict)
-    assert result["entry"]["data"] == {"host": "192.168.1.160"}
-    assert result["entry"]["unique_id"] == "1GU48T017973"
-
-    assert isinstance(result["data"], dict)
-    assert result["data"]["app"] == diagnostics_data["app"]
-    assert result["data"]["apps"] == diagnostics_data["apps"]
-    assert result["data"]["channel"] == diagnostics_data["channel"]
-    assert result["data"]["channels"] == diagnostics_data["channels"]
-    assert result["data"]["info"] == diagnostics_data["info"]
-    assert result["data"]["media"] == diagnostics_data["media"]
-
-    data_state = result["data"]["state"]
-    assert isinstance(data_state, dict)
-    assert data_state["available"] == diagnostics_data["state"]["available"]
-    assert data_state["standby"] == diagnostics_data["state"]["standby"]
+    assert (
+        await get_diagnostics_for_config_entry(hass, hass_client, init_integration)
+        == snapshot
+    )