diff --git a/openpilot/starpilot/ui/runtime_app.py b/openpilot/starpilot/ui/runtime_app.py
index 7dc50b1536..1382e94acb 100644
--- a/openpilot/starpilot/ui/runtime_app.py
+++ b/openpilot/starpilot/ui/runtime_app.py
@@ -1002,7 +1002,9 @@ class StarShellSession:
                                   compact_scroll_x=self.compact_scroll_x, sidebar_expanded=self.sidebar_expanded,
                                   menu_only=self.profile == Profile.COMPACT and mode == ShellMode.SETTINGS)
     if mode == ShellMode.ONROAD and self.profile == Profile.LARGE:
-      snapshot = replace(snapshot, onroad=replace(snapshot.onroad, viewport_width=getattr(self, '_onroad_width', 1860.0)))
+      width = getattr(self, '_onroad_width', 1860.0)
+      if snapshot.onroad.viewport_width != width:
+        snapshot = replace(snapshot, onroad=replace(snapshot.onroad, viewport_width=width))
     if mode == ShellMode.HOME:
       now = time.monotonic()
       previous = getattr(self, "_home_model", None)
diff --git a/openpilot/starpilot/ui/tests/test_developer_preview.py b/openpilot/starpilot/ui/tests/test_developer_preview.py
index 4260c974ea..208d439f5e 100644
--- a/openpilot/starpilot/ui/tests/test_developer_preview.py
+++ b/openpilot/starpilot/ui/tests/test_developer_preview.py
@@ -65,6 +65,8 @@ class DeveloperPreviewTests(unittest.TestCase):
     session._visual_preview_start_ns = 1_000_000_000
     with patch.object(runtime_app.time, "monotonic_ns", return_value=4_000_000_000):
       self.assertIs(session.snapshot(ShellMode.ONROAD), baseline)
+      self.assertIs(session.snapshot(ShellMode.ONROAD), baseline)
+      adapter.build.assert_called_once()
       session._visual_preview_flags = frozenset(("cem", "csc"))
       session._snapshot_cache = None
       observed = session.snapshot(ShellMode.ONROAD)
@@ -72,6 +74,13 @@ class DeveloperPreviewTests(unittest.TestCase):
       self.assertEqual(observed.onroad.visual_preview.curve_curvature, .008)
       self.assertEqual(replace(observed, onroad=baseline.onroad), baseline)
       self.assertIsNone(baseline.onroad.visual_preview)
+      self.assertIs(session.snapshot(ShellMode.ONROAD), observed)
+      session._onroad_width = 1560.0
+      session._snapshot_cache = None
+      resized = session.snapshot(ShellMode.ONROAD)
+      self.assertEqual(resized.onroad.viewport_width, 1560.0)
+      self.assertEqual(replace(resized.onroad, viewport_width=baseline.onroad.viewport_width), observed.onroad)
+      self.assertEqual(baseline.onroad.viewport_width, 1860.0)
 
 
 if __name__ == "__main__":
diff --git a/openpilot/starpilot/ui/tests/test_onroad_axes.py b/openpilot/starpilot/ui/tests/test_onroad_axes.py
index edce276f6a..1297416c92 100644
--- a/openpilot/starpilot/ui/tests/test_onroad_axes.py
+++ b/openpilot/starpilot/ui/tests/test_onroad_axes.py
@@ -114,7 +114,7 @@ class TestOnroadAxes(unittest.TestCase):
       for profile in (Profile.LARGE, Profile.COMPACT):
         with self.subTest(profile=profile, lateral=lateral, longitudinal=longitudinal):
           view = onroad.OnroadView.__new__(onroad.OnroadView)
-          object.__setattr__(view, "fonts", NS(profile=profile))
+          object.__setattr__(view, "fonts", NS(profile=profile, draw=Mock(), measure=Mock(return_value=NS(width=100, height=30))))
           view.camera_layer = Mock()
           view.extra_overlays = None
           view.alert = Mock()