diff --git a/api/test/unit/views/media_views_test.py b/api/test/unit/views/media_views_test.py
index d97a5b040..1953233dc 100644
--- a/api/test/unit/views/media_views_test.py
+++ b/api/test/unit/views/media_views_test.py
@@ -1,3 +1,6 @@
+import json
+from http.client import HTTPResponse
+from pathlib import Path
 from test.factory.models.image import ImageFactory
 from unittest import mock
 from urllib.error import HTTPError
@@ -7,6 +10,12 @@
 import pytest
 
 from catalog.api.models.image import Image
+from catalog.api.views.media_views import MediaViewSet
+
+
+_MOCK_IMAGE_PATH = Path(__file__).parent / ".." / ".." / "factory"
+_MOCK_IMAGE_BYTES = (_MOCK_IMAGE_PATH / "sample-image.jpg").read_bytes()
+_MOCK_IMAGE_INFO = json.loads((_MOCK_IMAGE_PATH / "sample-image-info.json").read_text())
 
 
 @pytest.fixture
@@ -38,3 +47,21 @@ def urlopen_503_response(url, **kwargs):
 
     assert response.status_code == 424
     mock_capture_exception.assert_called_once_with(error)
+
+
+@pytest.mark.django_db
+def test_thumb_sends_ua_header(api_client, image):
+    with mock.patch("catalog.api.views.media_views.urlopen") as urlopen_mock:
+        mock_res = mock.MagicMock(spec=HTTPResponse)
+        mock_res.status = 200
+        mock_res.headers = {}
+        urlopen_mock.return_value = mock_res
+        res = api_client.get(f"/v1/images/{image.identifier}/thumb/")
+
+    assert res.status_code == 200
+
+    urlopen_mock.assert_called_once()
+    assert (
+        urlopen_mock.call_args[0][0].headers["User-agent"]
+        == MediaViewSet.THUMBNAIL_PROXY_COMM_HEADERS["User-Agent"]
+    )