diff --git a/packages/core/src/config/projectRegistry.test.ts b/packages/core/src/config/projectRegistry.test.ts
index e7e532bb2b..c1e9c81709 100644
--- a/packages/core/src/config/projectRegistry.test.ts
+++ b/packages/core/src/config/projectRegistry.test.ts
@@ -294,6 +294,29 @@ describe('ProjectRegistry', () => {
     );
   });
 
+  it('safely handles ECOMPROMISED errors from proper-lockfile', async () => {
+    const registry = new ProjectRegistry(registryPath);
+    await registry.initialize();
+
+    let compromisedHandler: ((err: Error) => void) | undefined;
+    vi.mocked(lock).mockImplementation(async (file, options) => {
+      // @ts-expect-error onCompromised is not typed in the mock but is passed
+      compromisedHandler = options.onCompromised;
+      return vi.fn().mockResolvedValue(undefined);
+    });
+
+    await registry.getShortId('/foo');
+
+    expect(compromisedHandler).toBeDefined();
+
+    // Calling the handler should not throw
+    expect(() =>
+      compromisedHandler!(
+        Object.assign(new Error('Compromised'), { code: 'ECOMPROMISED' }),
+      ),
+    ).not.toThrow();
+  });
+
   it('throws if not initialized', async () => {
     const registry = new ProjectRegistry(registryPath);
     await expect(registry.getShortId('/foo')).rejects.toThrow(
diff --git a/packages/core/src/config/projectRegistry.ts b/packages/core/src/config/projectRegistry.ts
index 1aec0b7ad2..3e57032bea 100644
--- a/packages/core/src/config/projectRegistry.ts
+++ b/packages/core/src/config/projectRegistry.ts
@@ -179,6 +179,12 @@ export class ProjectRegistry {
         retries: Math.floor(LOCK_TIMEOUT_MS / LOCK_RETRY_DELAY_MS),
         minTimeout: LOCK_RETRY_DELAY_MS,
       },
+      onCompromised: (err) => {
+        debugLogger.debug(
+          'Project registry lock was compromised (likely released concurrently):',
+          err,
+        );
+      },
     });
 
     try {
diff --git a/packages/core/src/tools/trackerTools.test.ts b/packages/core/src/tools/trackerTools.test.ts
index 5ec59cdf60..516f652dd2 100644
--- a/packages/core/src/tools/trackerTools.test.ts
+++ b/packages/core/src/tools/trackerTools.test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
 import { Config } from '../config/config.js';
 import { MessageBus } from '../confirmation-bus/message-bus.js';
 import type { PolicyEngine } from '../policy/policy-engine.js';
@@ -37,7 +37,9 @@ describe('Tracker Tools Integration', () => {
       model: 'gemini-3-flash',
       debugMode: false,
     });
-    await config.initialize();
+    vi.spyOn(config.storage, 'getProjectTempTrackerDir').mockReturnValue(
+      tempDir,
+    );
     messageBus = new MessageBus(null as unknown as PolicyEngine, false);
   });
 
diff --git a/packages/core/src/utils/trust.test.ts b/packages/core/src/utils/trust.test.ts
index f5930972ff..fe40318d97 100644
--- a/packages/core/src/utils/trust.test.ts
+++ b/packages/core/src/utils/trust.test.ts
@@ -119,6 +119,28 @@ describe('Trust Utility (Core)', () => {
     expect(savedContent[finalKey]).toBe(TrustLevel.TRUST_FOLDER);
   });
 
+  it('safely handles ECOMPROMISED errors from proper-lockfile', async () => {
+    let compromisedHandler: ((err: Error) => void) | undefined;
+    vi.mocked(lock).mockImplementation(async (file, options) => {
+      // @ts-expect-error onCompromised is not typed in the mock but is passed
+      compromisedHandler = options.onCompromised;
+      return vi.fn().mockResolvedValue(undefined);
+    });
+
+    const folders = loadTrustedFolders();
+    const testPath = path.resolve('/new/trusted/path');
+    await folders.setValue(testPath, TrustLevel.TRUST_FOLDER);
+
+    expect(compromisedHandler).toBeDefined();
+
+    // Calling the handler should not throw
+    expect(() =>
+      compromisedHandler!(
+        Object.assign(new Error('Compromised'), { code: 'ECOMPROMISED' }),
+      ),
+    ).not.toThrow();
+  });
+
   it('should handle comments in JSON', () => {
     const content = `
     {
diff --git a/packages/core/src/utils/trust.ts b/packages/core/src/utils/trust.ts
index bf78746908..eb5791e8ec 100644
--- a/packages/core/src/utils/trust.ts
+++ b/packages/core/src/utils/trust.ts
@@ -14,6 +14,7 @@ import { normalizePath, isSubpath } from './paths.js';
 import { FatalConfigError, getErrorMessage } from './errors.js';
 import { coreEvents } from './events.js';
 import { ideContextStore } from '../ide/ideContext.js';
+import { debugLogger } from './debugLogger.js';
 
 export enum TrustLevel {
   TRUST_FOLDER = 'TRUST_FOLDER',
@@ -217,6 +218,13 @@ export class LoadedTrustedFolders {
         retries: 10,
         minTimeout: 100,
       },
+      onCompromised: (err) => {
+        // Ignore compromised lock since we expect another process might release it concurrently
+        debugLogger.debug(
+          'Trusted folders lock was compromised (likely released concurrently):',
+          err,
+        );
+      },
     });
 
     const normalizedPath = normalizePath(folderPath);