diff --git a/steward/hosts/routes.py b/steward/hosts/routes.py
index 7edf59c..49677f1 100644
--- a/steward/hosts/routes.py
+++ b/steward/hosts/routes.py
@@ -100,7 +100,7 @@ async def _list_page(add: dict | None = None):
         and not request.headers.get("HX-History-Restore-Request")
     resp = await make_response(await render_template(
         "hosts/_table.html" if partial else "hosts/list.html", **ctx))
-    resp.headers["Vary"] = "HX-Request"
+    resp.vary.add("HX-Request")
     return resp
 
 
diff --git a/tests/integration/test_hosts_list.py b/tests/integration/test_hosts_list.py
index 466dcb6..dc84c47 100644
--- a/tests/integration/test_hosts_list.py
+++ b/tests/integration/test_hosts_list.py
@@ -55,7 +55,7 @@ def test_the_hosts_list_filters_by_search_group_and_status(app):
         swap = {"HX-Request": "true", "HX-Target": "hosts-table"}
         resp = await client.get("/hosts/", query_string={"q": tag, "group": f"Swarm {tag}"}, headers=swap)
         table = await resp.get_data(as_text=True)
-        assert resp.headers["Vary"] == "HX-Request"
+        assert "HX-Request" in resp.headers["Vary"]
         assert 'class="filter-bar"' not in table and "<html" not in table
         assert f"swarm-{tag}" in table and f"lone-{tag}" not in table