diff --git a/apps/web/src/shell/workbench-list.tsx b/apps/web/src/shell/workbench-list.tsx
index fcba53bfd..f6566a7e5 100644
--- a/apps/web/src/shell/workbench-list.tsx
+++ b/apps/web/src/shell/workbench-list.tsx
@@ -301,6 +301,7 @@ function WorkbenchRow({
       // Revert the optimistic title on failure; the list will refetch on
       // the next scope selection and reconcile either way.
       setTitle(workbench.title);
+      toast(CHAT_STRINGS.workbenchRenameError);
     }
   }
 
diff --git a/packages/chat-ui/src/strings.test.ts b/packages/chat-ui/src/strings.test.ts
index ea2938039..aa1d4ffa3 100644
--- a/packages/chat-ui/src/strings.test.ts
+++ b/packages/chat-ui/src/strings.test.ts
@@ -15,6 +15,12 @@ describe("toast confirmation copy", () => {
     );
   });
 
+  test("rename failure tells the person to try again", () => {
+    expect(CHAT_STRINGS.workbenchRenameError).toBe(
+      "Couldn't rename that workbench — try again.",
+    );
+  });
+
   test("pin copy follows the state the workbench just entered", () => {
     expect(CHAT_STRINGS.workbenchPinnedToast(true, "Deploy notes")).toBe(
       "Pinned Deploy notes",
diff --git a/packages/chat-ui/src/strings.ts b/packages/chat-ui/src/strings.ts
index 604819b1a..91ff9f072 100644
--- a/packages/chat-ui/src/strings.ts
+++ b/packages/chat-ui/src/strings.ts
@@ -133,6 +133,7 @@ export const CHAT_STRINGS = {
   forkThreadOriginBanner: "Forked from a message in",
   workbenchCreatedToast: (title: string) => `Created · ${title}`,
   workbenchRenamedToast: (title: string) => `Renamed to ${title}`,
+  workbenchRenameError: "Couldn't rename that workbench — try again.",
   workbenchPinnedToast: (pinned: boolean, title: string) =>
     pinned ? `Pinned ${title}` : `Unpinned ${title}`,
   workbenchPinToggleError: (pinned: boolean) =>