diff --git a/src/commands/init.ts b/src/commands/init.ts
index 9f082a46..8e08fffd 100644
--- a/src/commands/init.ts
+++ b/src/commands/init.ts
@@ -81,12 +81,30 @@ export function ensureGitignoreEntries(cwd: string, entries: string[]): void {
 
 /**
  * Configure git to push notes automatically with regular pushes.
- * Adds refs/notes/* to existing push refspecs, preserving any user-configured refspecs.
+ * Adds refs/notes/* only when custom push refspecs already exist.
+ * This avoids overriding git's default push behavior in repos that
+ * rely on implicit push semantics (no remote.origin.push configured).
  * Idempotent - safe to call multiple times.
  */
-export function configureNotesPush(cwd: string): void {
+export type NotesPushConfigStatus =
+  | 'configured'
+  | 'already-configured'
+  | 'skipped-no-custom-push'
+  | 'skipped-no-origin';
+
+export function configureNotesPush(cwd: string): { status: NotesPushConfigStatus } {
   let existingRefspecs: string[] = [];
 
+  try {
+    execFileSync('git', ['remote', 'get-url', 'origin'], {
+      cwd,
+      encoding: 'utf8',
+      stdio: ['pipe', 'pipe', 'pipe'],
+    });
+  } catch {
+    return { status: 'skipped-no-origin' };
+  }
+
   try {
     // Get existing push refspecs
     const existing = execFileSync('git', ['config', '--local', '--get-all', 'remote.origin.push'], {
@@ -101,18 +119,16 @@ export function configureNotesPush(cwd: string): void {
 
     // Already has notes configured - nothing to do
     if (existingRefspecs.some((ref) => ref.includes('refs/notes'))) {
-      return;
+      return { status: 'already-configured' };
     }
   } catch {
-    // Config doesn't exist yet, proceed to set it
+    // Config doesn't exist yet
   }
 
-  // If no existing refspecs, add heads first
+  // Without explicit push refspecs, adding one would override default
+  // git push behavior (often current/upstream branch).
   if (existingRefspecs.length === 0) {
-    execFileSync('git', ['config', '--local', 'remote.origin.push', '+refs/heads/*:refs/heads/*'], {
-      cwd,
-      stdio: ['pipe', 'pipe', 'pipe'],
-    });
+    return { status: 'skipped-no-custom-push' };
   }
 
   // Add notes refspec (preserves existing refspecs)
@@ -120,6 +136,8 @@ export function configureNotesPush(cwd: string): void {
     cwd,
     stdio: ['pipe', 'pipe', 'pipe'],
   });
+
+  return { status: 'configured' };
 }
 
 /**
@@ -295,8 +313,17 @@ export async function initCommand(options: IInitCommandOptions, logger?: ILogger
     }
 
     // Configure git to push notes automatically with regular pushes
-    configureNotesPush(cwd);
-    console.log('✓ Configured git to push notes with commits');
+    const notesPush = configureNotesPush(cwd);
+    if (notesPush.status === 'configured') {
+      console.log('✓ Configured git to push notes with commits');
+    } else if (notesPush.status === 'already-configured') {
+      console.log('✓ Notes push already configured (skipped)');
+    } else if (notesPush.status === 'skipped-no-custom-push') {
+      console.log('i Skipped notes push auto-config to preserve default git push behavior');
+      console.log('  Use `git-mem sync --push` to publish notes, or add a custom remote.origin.push refspec.');
+    } else {
+      console.log('i No origin remote found; skipped notes push configuration');
+    }
   }
 
   // ── MCP config (skip if already exists) ────────────────────────
diff --git a/tests/unit/commands/init.test.ts b/tests/unit/commands/init.test.ts
index fa95a114..ead3d690 100644
--- a/tests/unit/commands/init.test.ts
+++ b/tests/unit/commands/init.test.ts
@@ -7,16 +7,36 @@
 
 import { describe, it } from 'node:test';
 import assert from 'node:assert/strict';
-import { mkdtempSync, writeFileSync, readFileSync } from 'fs';
+import { mkdtempSync, writeFileSync, readFileSync, mkdirSync } from 'fs';
 import { join } from 'path';
 import { tmpdir } from 'os';
 import { rmSync } from 'fs';
+import { execFileSync } from 'child_process';
 import {
   ensureGitignoreEntries,
+  configureNotesPush,
   readEnvApiKey,
   ensureEnvPlaceholder,
 } from '../../../src/commands/init';
 
+function git(args: string[], cwd: string): string {
+  return execFileSync('git', args, {
+    cwd,
+    encoding: 'utf8',
+    stdio: ['pipe', 'pipe', 'pipe'],
+  }).trim();
+}
+
+function getPushRefspecs(cwd: string): string[] {
+  try {
+    const output = git(['config', '--local', '--get-all', 'remote.origin.push'], cwd);
+    if (!output) return [];
+    return output.split('\n').filter(Boolean);
+  } catch {
+    return [];
+  }
+}
+
 // ── ensureGitignoreEntries ───────────────────────────────────────────
 
 describe('ensureGitignoreEntries', () => {
@@ -271,3 +291,82 @@ describe('ensureEnvPlaceholder', () => {
     }
   });
 });
+
+// ── configureNotesPush ────────────────────────────────────────────────
+
+describe('configureNotesPush', () => {
+  it('should skip when origin remote is not configured', () => {
+    const dir = mkdtempSync(join(tmpdir(), 'git-mem-notes-push-'));
+    try {
+      git(['init'], dir);
+      const result = configureNotesPush(dir);
+      assert.equal(result.status, 'skipped-no-origin');
+      assert.deepEqual(getPushRefspecs(dir), []);
+    } finally {
+      rmSync(dir, { recursive: true, force: true });
+    }
+  });
+
+  it('should skip when no custom remote.origin.push refspec exists', () => {
+    const base = mkdtempSync(join(tmpdir(), 'git-mem-notes-push-'));
+    const dir = join(base, 'repo');
+    const remote = join(base, 'remote.git');
+    try {
+      mkdirSync(dir, { recursive: true });
+      git(['init'], dir);
+      git(['init', '--bare', remote], base);
+      git(['remote', 'add', 'origin', remote], dir);
+
+      const result = configureNotesPush(dir);
+      assert.equal(result.status, 'skipped-no-custom-push');
+      assert.deepEqual(getPushRefspecs(dir), []);
+    } finally {
+      rmSync(base, { recursive: true, force: true });
+    }
+  });
+
+  it('should append notes refspec when custom push refspec exists', () => {
+    const base = mkdtempSync(join(tmpdir(), 'git-mem-notes-push-'));
+    const dir = join(base, 'repo');
+    const remote = join(base, 'remote.git');
+    try {
+      mkdirSync(dir, { recursive: true });
+      git(['init'], dir);
+      git(['init', '--bare', remote], base);
+      git(['remote', 'add', 'origin', remote], dir);
+      git(['config', '--local', 'remote.origin.push', 'refs/heads/main:refs/heads/main'], dir);
+
+      const result = configureNotesPush(dir);
+      assert.equal(result.status, 'configured');
+
+      const refspecs = getPushRefspecs(dir);
+      assert.ok(refspecs.includes('refs/heads/main:refs/heads/main'));
+      assert.ok(refspecs.includes('+refs/notes/*:refs/notes/*'));
+    } finally {
+      rmSync(base, { recursive: true, force: true });
+    }
+  });
+
+  it('should be idempotent when notes refspec already exists', () => {
+    const base = mkdtempSync(join(tmpdir(), 'git-mem-notes-push-'));
+    const dir = join(base, 'repo');
+    const remote = join(base, 'remote.git');
+    try {
+      mkdirSync(dir, { recursive: true });
+      git(['init'], dir);
+      git(['init', '--bare', remote], base);
+      git(['remote', 'add', 'origin', remote], dir);
+      git(['config', '--local', '--add', 'remote.origin.push', 'refs/heads/main:refs/heads/main'], dir);
+      git(['config', '--local', '--add', 'remote.origin.push', '+refs/notes/*:refs/notes/*'], dir);
+
+      const result = configureNotesPush(dir);
+      assert.equal(result.status, 'already-configured');
+
+      const refspecs = getPushRefspecs(dir);
+      const notesRefs = refspecs.filter((ref) => ref === '+refs/notes/*:refs/notes/*');
+      assert.equal(notesRefs.length, 1);
+    } finally {
+      rmSync(base, { recursive: true, force: true });
+    }
+  });
+});