diff --git a/apps/web/src/components/chat/useRightPanelActions.browser.test.tsx b/apps/web/src/components/chat/useRightPanelActions.browser.test.tsx
new file mode 100644
index 0000000000000..9dc1a10fd53ed
--- /dev/null
+++ b/apps/web/src/components/chat/useRightPanelActions.browser.test.tsx
@@ -0,0 +1,63 @@
+import { scopeThreadRef } from "@t3tools/client-runtime/environment";
+import { EnvironmentId, ThreadId } from "@t3tools/contracts";
+import { expect, it } from "vite-plus/test";
+
+import { render } from "../../../test/render";
+import { __testing } from "../../previewStateStore";
+import { selectThreadRightPanelState, useRightPanelStore } from "../../rightPanelStore";
+import { useDeviceState } from "../../state/device";
+import { useRightPanelActions } from "./useRightPanelActions";
+
+it("remembers the browser's maximized size when toggling the side panel", async () => {
+  const ref = scopeThreadRef(EnvironmentId.make("panel-test"), ThreadId.make("panel-test"));
+  useRightPanelStore.setState({ byThreadKey: {} });
+  useRightPanelStore.getState().openBrowser(ref, null);
+  useRightPanelStore.getState().setMaximized(ref, true);
+
+  function Panel() {
+    const panel = useRightPanelStore((state) =>
+      selectThreadRightPanelState(state.byThreadKey, ref),
+    );
+    const device = useDeviceState(null);
+    const actions = useRightPanelActions({
+      activeThreadRef: ref,
+      activeProject: null,
+      activeRightPanelSurface:
+        panel.surfaces.find((surface) => surface.id === panel.activeSurfaceId) ?? null,
+      activePreviewState: __testing.EMPTY_THREAD_PREVIEW_STATE,
+      deviceState: device.state,
+      deviceStateLoaded: false,
+      pullRequestPanelTarget: null,
+      threadPanelPresentation: "inline",
+      isServerThread: true,
+      embedded: false,
+      isGitRepo: false,
+      browserAvailable: true,
+      canOperatePreview: true,
+      diffOpen: false,
+      previewPanelOpen: panel.isOpen,
+      rightPanelOpen: panel.isOpen,
+      canMaximizeRightPanel: panel.isOpen,
+      rightPanelMaximized: panel.isOpen && panel.maximized === true,
+      supportsPullRequests: false,
+      pullRequestsSurfaceAvailable: false,
+      gitCwd: null,
+      activeProjectCwd: null,
+      explicitDiffOpenRef: { current: null },
+      onDiffPanelOpen: undefined,
+      closeRightPanelSurface: () => undefined,
+    });
+    return <button onClick={actions.toggleRightPanelStable}>Toggle panel</button>;
+  }
+
+  await using screen = await render(<Panel />);
+  const toggle = screen.getByRole("button", { name: "Toggle panel" });
+  await toggle.click();
+  expect(selectThreadRightPanelState(useRightPanelStore.getState().byThreadKey, ref).isOpen).toBe(
+    false,
+  );
+  await toggle.click();
+  const reopened = selectThreadRightPanelState(useRightPanelStore.getState().byThreadKey, ref);
+  expect(reopened.isOpen).toBe(true);
+  expect(reopened.maximized).toBe(true);
+});
diff --git a/apps/web/src/components/chat/useRightPanelActions.ts b/apps/web/src/components/chat/useRightPanelActions.ts
index 0f8e8e3ce303f..358cfe9374054 100644
--- a/apps/web/src/components/chat/useRightPanelActions.ts
+++ b/apps/web/src/components/chat/useRightPanelActions.ts
@@ -179,7 +179,6 @@ export function useRightPanelActions(input: RightPanelActionsInput) {
           deviceStateLoaded ? deviceState : null,
         );
       }
-      useRightPanelStore.getState().setMaximized(activeThreadRef, false);
       useRightPanelStore.getState().close(activeThreadRef);
     }
   };