diff --git a/agent-teams-controller/src/internal/workSync.js b/agent-teams-controller/src/internal/workSync.js
index 63036fc6..5ac48411 100644
--- a/agent-teams-controller/src/internal/workSync.js
+++ b/agent-teams-controller/src/internal/workSync.js
@@ -2,6 +2,7 @@ const fs = require('fs');
 const path = require('path');
 const crypto = require('crypto');
 const runtimeHelpers = require('./runtimeHelpers.js');
+const { withFileLockSync } = require('./fileLock.js');
 
 const DEFAULT_WAIT_TIMEOUT_MS = 10000;
 const MIN_WAIT_TIMEOUT_MS = 1000;
@@ -173,25 +174,28 @@ function writePendingReportFile(filePath, data) {
 
 function appendPendingReportIntent(context, body, reason) {
   const filePath = path.join(context.paths.teamDir, '.member-work-sync', 'pending-reports.json');
-  const data = readPendingReportFile(filePath);
-  const request = {
-    ...body,
-    source: 'mcp',
-  };
-  const id = buildPendingIntentId(request);
-  const current = data.intents[id];
-  if (!current || current.status === 'pending') {
-    data.intents[id] = {
-      id,
-      teamName: body.teamName,
-      memberName: body.memberName,
-      request,
-      reason,
-      status: 'pending',
-      recordedAt: current && current.recordedAt ? current.recordedAt : new Date().toISOString(),
+  const { id } = withFileLockSync(filePath, () => {
+    const data = readPendingReportFile(filePath);
+    const request = {
+      ...body,
+      source: 'mcp',
     };
-    writePendingReportFile(filePath, data);
-  }
+    const intentId = buildPendingIntentId(request);
+    const current = data.intents[intentId];
+    if (!current || current.status === 'pending') {
+      data.intents[intentId] = {
+        id: intentId,
+        teamName: body.teamName,
+        memberName: body.memberName,
+        request,
+        reason,
+        status: 'pending',
+        recordedAt: current && current.recordedAt ? current.recordedAt : new Date().toISOString(),
+      };
+      writePendingReportFile(filePath, data);
+    }
+    return { id: intentId };
+  });
   return {
     accepted: false,
     pendingValidation: true,
diff --git a/src/features/member-work-sync/main/infrastructure/JsonMemberWorkSyncStore.ts b/src/features/member-work-sync/main/infrastructure/JsonMemberWorkSyncStore.ts
index f5329e4d..ec2df82e 100644
--- a/src/features/member-work-sync/main/infrastructure/JsonMemberWorkSyncStore.ts
+++ b/src/features/member-work-sync/main/infrastructure/JsonMemberWorkSyncStore.ts
@@ -2,6 +2,7 @@ import { atomicWriteAsync } from '@main/utils/atomicWrite';
 import { createHash } from 'crypto';
 import { mkdir, readFile, rename } from 'fs/promises';
 
+import { withFileLock } from '@main/services/team/fileLock';
 import type {
   MemberWorkSyncReportIntent,
   MemberWorkSyncReportRequest,
@@ -106,34 +107,38 @@ export class JsonMemberWorkSyncStore
 
   async write(status: MemberWorkSyncStatus): Promise<void> {
     await this.enqueue(status.teamName, async () => {
-      const existing = await this.readFile(status.teamName);
-      existing.members[normalizeMemberKey(status.memberName)] = status;
-      await mkdir(this.paths.getTeamDir(status.teamName), { recursive: true });
-      await atomicWriteAsync(
-        this.paths.getStatusPath(status.teamName),
-        JSON.stringify(existing, null, 2)
-      );
+      await withFileLock(this.paths.getStatusPath(status.teamName), async () => {
+        const existing = await this.readFile(status.teamName);
+        existing.members[normalizeMemberKey(status.memberName)] = status;
+        await mkdir(this.paths.getTeamDir(status.teamName), { recursive: true });
+        await atomicWriteAsync(
+          this.paths.getStatusPath(status.teamName),
+          JSON.stringify(existing, null, 2)
+        );
+      });
     });
   }
 
   async appendPendingReport(request: MemberWorkSyncReportRequest, reason: string): Promise<void> {
     const id = buildPendingReportIntentId(request);
     await this.enqueue(request.teamName, async () => {
-      const existing = await this.readPendingFile(request.teamName);
-      const current = existing.intents[id];
-      if (current && current.status !== 'pending') {
-        return;
-      }
-      existing.intents[id] = {
-        id,
-        teamName: request.teamName,
-        memberName: request.memberName,
-        request,
-        reason: current?.reason ?? reason,
-        status: 'pending',
-        recordedAt: current?.recordedAt ?? new Date().toISOString(),
-      };
-      await this.writePendingFile(request.teamName, existing);
+      await withFileLock(this.paths.getPendingReportsPath(request.teamName), async () => {
+        const existing = await this.readPendingFile(request.teamName);
+        const current = existing.intents[id];
+        if (current && current.status !== 'pending') {
+          return;
+        }
+        existing.intents[id] = {
+          id,
+          teamName: request.teamName,
+          memberName: request.memberName,
+          request,
+          reason: current?.reason ?? reason,
+          status: 'pending',
+          recordedAt: current?.recordedAt ?? new Date().toISOString(),
+        };
+        await this.writePendingFile(request.teamName, existing);
+      });
     });
   }
 
@@ -154,18 +159,20 @@ export class JsonMemberWorkSyncStore
     }
   ): Promise<void> {
     await this.enqueue(teamName, async () => {
-      const existing = await this.readPendingFile(teamName);
-      const current = existing.intents[id];
-      if (!current || current.status !== 'pending') {
-        return;
-      }
-      existing.intents[id] = {
-        ...current,
-        status: result.status,
-        resultCode: result.resultCode,
-        processedAt: result.processedAt,
-      };
-      await this.writePendingFile(teamName, existing);
+      await withFileLock(this.paths.getPendingReportsPath(teamName), async () => {
+        const existing = await this.readPendingFile(teamName);
+        const current = existing.intents[id];
+        if (!current || current.status !== 'pending') {
+          return;
+        }
+        existing.intents[id] = {
+          ...current,
+          status: result.status,
+          resultCode: result.resultCode,
+          processedAt: result.processedAt,
+        };
+        await this.writePendingFile(teamName, existing);
+      });
     });
   }