diff --git a/orchestrator/src/server/repositories/ghostwriter.ts b/orchestrator/src/server/repositories/ghostwriter.ts
index 47ab607..fec863d 100644
--- a/orchestrator/src/server/repositories/ghostwriter.ts
+++ b/orchestrator/src/server/repositories/ghostwriter.ts
@@ -341,3 +341,28 @@ export async function completeRun(
 
   return getRunById(runId);
 }
+
+export async function completeRunIfRunning(
+  runId: string,
+  input: {
+    status: Exclude<JobChatRunStatus, "running">;
+    errorCode?: string | null;
+    errorMessage?: string | null;
+  },
+): Promise<JobChatRun | null> {
+  const nowEpoch = Date.now();
+  const nowIso = new Date(nowEpoch).toISOString();
+
+  await db
+    .update(jobChatRuns)
+    .set({
+      status: input.status,
+      completedAt: nowEpoch,
+      errorCode: input.errorCode ?? null,
+      errorMessage: input.errorMessage ?? null,
+      updatedAt: nowIso,
+    })
+    .where(and(eq(jobChatRuns.id, runId), eq(jobChatRuns.status, "running")));
+
+  return getRunById(runId);
+}
diff --git a/orchestrator/src/server/services/ghostwriter.test.ts b/orchestrator/src/server/services/ghostwriter.test.ts
index 069881f..ccf9cd1 100644
--- a/orchestrator/src/server/services/ghostwriter.test.ts
+++ b/orchestrator/src/server/services/ghostwriter.test.ts
@@ -14,6 +14,7 @@ const mocks = vi.hoisted(() => ({
     createRun: vi.fn(),
     updateMessage: vi.fn(),
     completeRun: vi.fn(),
+    completeRunIfRunning: vi.fn(),
     getMessageById: vi.fn(),
     getLatestAssistantMessage: vi.fn(),
     getRunById: vi.fn(),
@@ -52,6 +53,7 @@ vi.mock("../repositories/ghostwriter", () => ({
   createRun: mocks.repo.createRun,
   updateMessage: mocks.repo.updateMessage,
   completeRun: mocks.repo.completeRun,
+  completeRunIfRunning: mocks.repo.completeRunIfRunning,
   getMessageById: mocks.repo.getMessageById,
   getLatestAssistantMessage: mocks.repo.getLatestAssistantMessage,
   getRunById: mocks.repo.getRunById,
@@ -148,6 +150,21 @@ describe("ghostwriter service", () => {
       updatedAt: new Date().toISOString(),
     });
     mocks.repo.completeRun.mockResolvedValue(null);
+    mocks.repo.completeRunIfRunning.mockResolvedValue({
+      id: "run-1",
+      threadId: "thread-1",
+      jobId: "job-1",
+      status: "cancelled",
+      model: "model-a",
+      provider: "openrouter",
+      errorCode: "REQUEST_TIMEOUT",
+      errorMessage: "Generation cancelled by user",
+      startedAt: Date.now(),
+      completedAt: Date.now(),
+      requestId: "req-123",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    });
     mocks.repo.updateMessage.mockResolvedValue(baseAssistantMessage);
     mocks.repo.getMessageById.mockResolvedValue(baseAssistantMessage);
     mocks.repo.listMessagesForThread.mockResolvedValue([
@@ -355,6 +372,48 @@ describe("ghostwriter service", () => {
 
     expect(result).toEqual({ cancelled: false, alreadyFinished: true });
     expect(mocks.repo.completeRun).not.toHaveBeenCalled();
+    expect(mocks.repo.completeRunIfRunning).not.toHaveBeenCalled();
+  });
+
+  it("returns alreadyFinished when run completes before cancel write", async () => {
+    mocks.repo.getRunById.mockResolvedValue({
+      id: "run-race",
+      threadId: "thread-1",
+      jobId: "job-1",
+      status: "running",
+      model: "model-a",
+      provider: "openrouter",
+      errorCode: null,
+      errorMessage: null,
+      startedAt: Date.now(),
+      completedAt: null,
+      requestId: "req-123",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    });
+    mocks.repo.completeRunIfRunning.mockResolvedValue({
+      id: "run-race",
+      threadId: "thread-1",
+      jobId: "job-1",
+      status: "completed",
+      model: "model-a",
+      provider: "openrouter",
+      errorCode: null,
+      errorMessage: null,
+      startedAt: Date.now(),
+      completedAt: Date.now(),
+      requestId: "req-123",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    });
+
+    const result = await cancelRun({
+      jobId: "job-1",
+      threadId: "thread-1",
+      runId: "run-race",
+    });
+
+    expect(result).toEqual({ cancelled: false, alreadyFinished: true });
   });
 
   it("maps createRun unique constraint races to conflict", async () => {
diff --git a/orchestrator/src/server/services/ghostwriter.ts b/orchestrator/src/server/services/ghostwriter.ts
index 908b0c6..13e24b0 100644
--- a/orchestrator/src/server/services/ghostwriter.ts
+++ b/orchestrator/src/server/services/ghostwriter.ts
@@ -562,12 +562,19 @@ export async function cancelRun(input: {
     controller.abort();
   }
 
-  await jobChatRepo.completeRun(input.runId, {
+  const runAfterCancel = await jobChatRepo.completeRunIfRunning(input.runId, {
     status: "cancelled",
     errorCode: "REQUEST_TIMEOUT",
     errorMessage: "Generation cancelled by user",
   });
 
+  if (!runAfterCancel || runAfterCancel.status !== "cancelled") {
+    return {
+      cancelled: false,
+      alreadyFinished: true,
+    };
+  }
+
   return {
     cancelled: true,
     alreadyFinished: false,