diff --git a/src/features/chat/panel/shell.dom.tsx b/src/features/chat/panel/shell.dom.tsx
index 9d61748a..2a4073d0 100644
--- a/src/features/chat/panel/shell.dom.tsx
+++ b/src/features/chat/panel/shell.dom.tsx
@@ -42,8 +42,7 @@ export function renderChatPanelShell(container: HTMLElement, props: ChatPanelShe
   container.addClass("codex-panel");
   const existing = shellMounts.get(container);
   const mount = existing?.stateStore === props.stateStore ? existing : createShellMount(container, props);
-  mount.props = props;
-  renderMountedShell(container, mount);
+  renderMountedShell(container, mount, props);
 }
 
 export function unmountChatPanelShell(container: HTMLElement | null): void {
@@ -75,13 +74,14 @@ function createShellMount(container: HTMLElement, props: ChatPanelShellProps): C
   return mount;
 }
 
-function renderMountedShell(container: HTMLElement, mount: ChatPanelShellMount): void {
+function renderMountedShell(container: HTMLElement, mount: ChatPanelShellMount, props: ChatPanelShellProps): void {
   if (!uiRootIntact(container, mount.props.showToolbar)) {
     unmountUiRoot(container);
     container.replaceChildren();
   }
   syncStatusBarClearance(container);
-  renderUiRoot(container, <ChatPanelShell {...mount.props} shellReadModelBinding={mount.shellReadModelBinding} />);
+  renderUiRoot(container, <ChatPanelShell {...props} shellReadModelBinding={mount.shellReadModelBinding} />);
+  mount.props = props;
 }
 
 function uiRootIntact(container: HTMLElement, showToolbar: boolean): boolean {
diff --git a/tests/features/chat/panel/shell.test.tsx b/tests/features/chat/panel/shell.test.tsx
index 7ac7187f..4197c18c 100644
--- a/tests/features/chat/panel/shell.test.tsx
+++ b/tests/features/chat/panel/shell.test.tsx
@@ -282,8 +282,9 @@ describe("ChatPanelShell", () => {
     });
   });
 
-  it("removes and restores the toolbar from shell props without replacing the body regions", async () => {
+  it("removes and restores the toolbar without losing composer or thread viewport state", async () => {
     const store = createChatStateStore();
+    store.dispatch({ type: "composer/draft-set", draft: "toolbar continuity" });
     const container = document.createElement("div");
     document.body.appendChild(container);
     const parts = shellParts();
@@ -296,6 +297,12 @@ describe("ChatPanelShell", () => {
     expect(container.querySelector(".codex-panel__toolbar")).toBeNull();
     expect(container.querySelector(".codex-panel__region--thread-stream")).not.toBeNull();
     expect(container.querySelector(".codex-panel__region--composer")).not.toBeNull();
+    const initialComposer = composer(container);
+    const initialThreadStream = container.querySelector<HTMLElement>(".codex-panel__region--thread-stream");
+    if (!initialThreadStream) throw new Error("Missing thread stream");
+    initialComposer.focus();
+    initialComposer.setSelectionRange(2, 9);
+    initialThreadStream.scrollTop = 42;
 
     await act(async () => {
       renderChatPanelShell(container, { stateStore: store, showToolbar: true, parts });
@@ -304,6 +311,21 @@ describe("ChatPanelShell", () => {
 
     expect(container.querySelector(".codex-panel__toolbar")).not.toBeNull();
     expect(container.firstElementChild?.classList.contains("codex-panel__toolbar")).toBe(true);
+    expect(document.activeElement).toBe(composer(container));
+    expect(composer(container).selectionStart).toBe(2);
+    expect(composer(container).selectionEnd).toBe(9);
+    expect(container.querySelector<HTMLElement>(".codex-panel__region--thread-stream")?.scrollTop).toBe(42);
+
+    await act(async () => {
+      renderChatPanelShell(container, { stateStore: store, showToolbar: false, parts });
+      await settleShellEffects();
+    });
+
+    expect(container.querySelector(".codex-panel__toolbar")).toBeNull();
+    expect(document.activeElement).toBe(composer(container));
+    expect(composer(container).selectionStart).toBe(2);
+    expect(composer(container).selectionEnd).toBe(9);
+    expect(container.querySelector<HTMLElement>(".codex-panel__region--thread-stream")?.scrollTop).toBe(42);
 
     await act(async () => {
       unmountChatPanelShell(container);