diff --git a/tests/dashboard/test_web_server.py b/tests/dashboard/test_web_server.py
index a22f4a8b2a..e481a1b273 100644
--- a/tests/dashboard/test_web_server.py
+++ b/tests/dashboard/test_web_server.py
@@ -579,3 +579,86 @@ def test_start_web_server_with_unix_socket(tmp_path: Path) -> None:
         mock_server_class.assert_called_once_with(app)
         mock_bind.assert_called_once_with(str(socket_path), mode=0o666)
         server.add_socket.assert_called_once()
+
+
+# Tests for build_cache_arguments function
+
+
+def test_build_cache_arguments_no_entry(mock_dashboard: Mock) -> None:
+    """Test with no entry returns empty list."""
+    result = web_server.build_cache_arguments(None, mock_dashboard, 0.0)
+    assert result == []
+
+
+def test_build_cache_arguments_no_address_no_name(mock_dashboard: Mock) -> None:
+    """Test with entry but no address or name."""
+    entry = Mock(spec=web_server.DashboardEntry)
+    entry.address = None
+    entry.name = None
+    result = web_server.build_cache_arguments(entry, mock_dashboard, 0.0)
+    assert result == []
+
+
+def test_build_cache_arguments_mdns_address_cached(mock_dashboard: Mock) -> None:
+    """Test with .local address that has cached mDNS results."""
+    entry = Mock(spec=web_server.DashboardEntry)
+    entry.address = "device.local"
+    entry.name = None
+    mock_dashboard.mdns_status = Mock()
+    mock_dashboard.mdns_status.get_cached_addresses.return_value = [
+        "192.168.1.10",
+        "fe80::1",
+    ]
+
+    result = web_server.build_cache_arguments(entry, mock_dashboard, 0.0)
+
+    assert result == [
+        "--mdns-address-cache",
+        "device.local=192.168.1.10,fe80::1",
+    ]
+    mock_dashboard.mdns_status.get_cached_addresses.assert_called_once_with(
+        "device.local"
+    )
+
+
+def test_build_cache_arguments_dns_address_cached(mock_dashboard: Mock) -> None:
+    """Test with non-.local address that has cached DNS results."""
+    entry = Mock(spec=web_server.DashboardEntry)
+    entry.address = "example.com"
+    entry.name = None
+    mock_dashboard.dns_cache = Mock()
+    mock_dashboard.dns_cache.get_cached_addresses.return_value = [
+        "93.184.216.34",
+        "2606:2800:220:1:248:1893:25c8:1946",
+    ]
+
+    now = 100.0
+    result = web_server.build_cache_arguments(entry, mock_dashboard, now)
+
+    # IPv6 addresses are sorted before IPv4
+    assert result == [
+        "--dns-address-cache",
+        "example.com=2606:2800:220:1:248:1893:25c8:1946,93.184.216.34",
+    ]
+    mock_dashboard.dns_cache.get_cached_addresses.assert_called_once_with(
+        "example.com", now
+    )
+
+
+def test_build_cache_arguments_name_without_address(mock_dashboard: Mock) -> None:
+    """Test with name but no address - should check mDNS with .local suffix."""
+    entry = Mock(spec=web_server.DashboardEntry)
+    entry.name = "my-device"
+    entry.address = None
+    mock_dashboard.mdns_status = Mock()
+    mock_dashboard.mdns_status.get_cached_addresses.return_value = ["192.168.1.20"]
+
+    result = web_server.build_cache_arguments(entry, mock_dashboard, 0.0)
+
+    assert result == [
+        "--mdns-address-cache",
+        "my-device.local=192.168.1.20",
+    ]
+    mock_dashboard.mdns_status.get_cached_addresses.assert_called_once_with(
+        "my-device.local"
+    )