diff --git a/src/__tests__/autoCommit.test.ts b/src/__tests__/autoCommit.test.ts
index 66c22d0..0cc40f5 100644
--- a/src/__tests__/autoCommit.test.ts
+++ b/src/__tests__/autoCommit.test.ts
@@ -30,7 +30,7 @@ describe('autoCommitAndPush', () => {
       return Buffer.from('');
     });
 
-    const result = autoCommitAndPush('/tmp/clone', 'my-task');
+    const result = autoCommitAndPush('/tmp/clone', 'my-task', '/project');
 
     expect(result.success).toBe(true);
     expect(result.commitHash).toBe('abc1234');
@@ -50,10 +50,10 @@ describe('autoCommitAndPush', () => {
       expect.objectContaining({ cwd: '/tmp/clone' })
     );
 
-    // Verify push was called
+    // Verify push was called with projectDir directly (no origin remote)
     expect(mockExecFileSync).toHaveBeenCalledWith(
       'git',
-      ['push', 'origin', 'HEAD'],
+      ['push', '/project', 'HEAD'],
       expect.objectContaining({ cwd: '/tmp/clone' })
     );
   });
@@ -67,7 +67,7 @@ describe('autoCommitAndPush', () => {
       return Buffer.from('');
     });
 
-    const result = autoCommitAndPush('/tmp/clone', 'my-task');
+    const result = autoCommitAndPush('/tmp/clone', 'my-task', '/project');
 
     expect(result.success).toBe(true);
     expect(result.commitHash).toBeUndefined();
@@ -90,7 +90,7 @@ describe('autoCommitAndPush', () => {
     // Verify push was NOT called
     expect(mockExecFileSync).not.toHaveBeenCalledWith(
       'git',
-      ['push', 'origin', 'HEAD'],
+      ['push', '/project', 'HEAD'],
       expect.anything()
     );
   });
@@ -100,7 +100,7 @@ describe('autoCommitAndPush', () => {
       throw new Error('git error: not a git repository');
     });
 
-    const result = autoCommitAndPush('/tmp/clone', 'my-task');
+    const result = autoCommitAndPush('/tmp/clone', 'my-task', '/project');
 
     expect(result.success).toBe(false);
     expect(result.commitHash).toBeUndefined();
@@ -120,7 +120,7 @@ describe('autoCommitAndPush', () => {
       return Buffer.from('');
     });
 
-    autoCommitAndPush('/tmp/clone', 'test-task');
+    autoCommitAndPush('/tmp/clone', 'test-task', '/project');
 
     // Find the commit call
     const commitCall = mockExecFileSync.mock.calls.find(
@@ -145,7 +145,7 @@ describe('autoCommitAndPush', () => {
       return Buffer.from('');
     });
 
-    autoCommitAndPush('/tmp/clone', '認証機能を追加する');
+    autoCommitAndPush('/tmp/clone', '認証機能を追加する', '/project');
 
     const commitCall = mockExecFileSync.mock.calls.find(
       call => (call[1] as string[])[0] === 'commit'
diff --git a/src/cli.ts b/src/cli.ts
index 68dae7b..8fba1d9 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -228,7 +228,7 @@ program
       const taskSuccess = await executeTask(task, execCwd, selectedWorkflow, cwd);
 
       if (taskSuccess && isWorktree) {
-        const commitResult = autoCommitAndPush(execCwd, task);
+        const commitResult = autoCommitAndPush(execCwd, task, cwd);
         if (commitResult.success && commitResult.commitHash) {
           success(`Auto-committed & pushed: ${commitResult.commitHash}`);
         } else if (!commitResult.success) {
diff --git a/src/commands/reviewTasks.ts b/src/commands/reviewTasks.ts
index a5621b9..56d9551 100644
--- a/src/commands/reviewTasks.ts
+++ b/src/commands/reviewTasks.ts
@@ -317,7 +317,7 @@ export async function instructBranch(
 
     // 6. Auto-commit+push if successful
     if (taskSuccess) {
-      const commitResult = autoCommitAndPush(clone.path, item.taskSlug);
+      const commitResult = autoCommitAndPush(clone.path, item.taskSlug, projectDir);
       if (commitResult.success && commitResult.commitHash) {
         info(`Auto-committed & pushed: ${commitResult.commitHash}`);
       } else if (!commitResult.success) {
diff --git a/src/commands/taskExecution.ts b/src/commands/taskExecution.ts
index 975099e..fe71051 100644
--- a/src/commands/taskExecution.ts
+++ b/src/commands/taskExecution.ts
@@ -81,7 +81,7 @@ export async function executeAndCompleteTask(
     const completedAt = new Date().toISOString();
 
     if (taskSuccess && isWorktree) {
-      const commitResult = autoCommitAndPush(execCwd, task.name);
+      const commitResult = autoCommitAndPush(execCwd, task.name, cwd);
       if (commitResult.success && commitResult.commitHash) {
         info(`Auto-committed & pushed: ${commitResult.commitHash}`);
       } else if (!commitResult.success) {
diff --git a/src/task/autoCommit.ts b/src/task/autoCommit.ts
index 7910257..3a358ad 100644
--- a/src/task/autoCommit.ts
+++ b/src/task/autoCommit.ts
@@ -32,8 +32,9 @@ export interface AutoCommitResult {
  *
  * @param cloneCwd - The clone directory
  * @param taskName - Task name used in commit message
+ * @param projectDir - The main project directory (push target)
  */
-export function autoCommitAndPush(cloneCwd: string, taskName: string): AutoCommitResult {
+export function autoCommitAndPush(cloneCwd: string, taskName: string, projectDir: string): AutoCommitResult {
   log.info('Auto-commit starting', { cwd: cloneCwd, taskName });
 
   try {
@@ -71,13 +72,13 @@ export function autoCommitAndPush(cloneCwd: string, taskName: string): AutoCommi
 
     log.info('Auto-commit created', { commitHash, message: commitMessage });
 
-    // Push to origin so the branch is reflected in the main repo
-    execFileSync('git', ['push', 'origin', 'HEAD'], {
+    // Push directly to the main repo (origin was removed to isolate the clone)
+    execFileSync('git', ['push', projectDir, 'HEAD'], {
       cwd: cloneCwd,
       stdio: 'pipe',
     });
 
-    log.info('Pushed to origin');
+    log.info('Pushed to main repo', { projectDir });
 
     return {
       success: true,
diff --git a/src/task/worktree.ts b/src/task/worktree.ts
index ce39595..b228787 100644
--- a/src/task/worktree.ts
+++ b/src/task/worktree.ts
@@ -137,6 +137,12 @@ export function createSharedClone(projectDir: string, options: WorktreeOptions):
     stdio: 'pipe',
   });
 
+  // Remove origin remote so Claude Code SDK won't follow it back to the main repo
+  execFileSync('git', ['remote', 'remove', 'origin'], {
+    cwd: clonePath,
+    stdio: 'pipe',
+  });
+
   // Checkout branch
   if (branchExists(clonePath, branch)) {
     execFileSync('git', ['checkout', branch], {
@@ -185,6 +191,12 @@ export function createTempCloneForBranch(projectDir: string, branch: string): Wo
     stdio: 'pipe',
   });
 
+  // Remove origin remote so Claude Code SDK won't follow it back to the main repo
+  execFileSync('git', ['remote', 'remove', 'origin'], {
+    cwd: clonePath,
+    stdio: 'pipe',
+  });
+
   execFileSync('git', ['checkout', branch], {
     cwd: clonePath,
     stdio: 'pipe',