diff --git a/scripts/playbook.py b/scripts/playbook.py
index e486baac..08eb25e9 100644
--- a/scripts/playbook.py
+++ b/scripts/playbook.py
@@ -760,6 +760,10 @@ _CLAUDE_BLOCK_END = "<!-- playbook:claude:end -->"
 _CLAUDE_MD_CANDIDATES = ["CLAUDE.md", ".claude/CLAUDE.md"]
 
 
+def _claude_block_needs_heading(text: str) -> bool:
+    return text.lstrip().startswith(_CLAUDE_BLOCK_START)
+
+
 def sync_claude_md(project_root: Path, config: dict) -> None:
     claude_md_config = config.get("playbook", {}).get("claude_md")
 
@@ -796,7 +800,9 @@ def sync_claude_md(project_root: Path, config: dict) -> None:
     if not claude_md.exists():
         ensure_dir(claude_md.parent)
         claude_md.write_text(
-            "\n".join(block_lines) + "\n", encoding="utf-8", newline="\n"
+            "# CLAUDE.md\n\n" + "\n".join(block_lines) + "\n",
+            encoding="utf-8",
+            newline="\n",
         )
         log(f"Created {claude_md.relative_to(project_root)} with playbook block.")
         return
@@ -819,9 +825,10 @@ def sync_claude_md(project_root: Path, config: dict) -> None:
                     in_block = False
                 continue
             updated.append(line)
-        claude_md.write_text(
-            "\n".join(updated) + "\n", encoding="utf-8", newline="\n"
-        )
+        updated_text = "\n".join(updated) + "\n"
+        if _claude_block_needs_heading(updated_text):
+            updated_text = "# CLAUDE.md\n\n" + updated_text.lstrip()
+        claude_md.write_text(updated_text, encoding="utf-8", newline="\n")
         log("Updated CLAUDE.md (playbook block).")
     elif "@AGENTS.md" in text:
         log("Skip: CLAUDE.md already references AGENTS.md")
diff --git a/tests/cli/test_playbook_cli.py b/tests/cli/test_playbook_cli.py
index 474273c5..92d69bfd 100644
--- a/tests/cli/test_playbook_cli.py
+++ b/tests/cli/test_playbook_cli.py
@@ -607,6 +607,7 @@ project_name = "Demo"
             claude_md = Path(tmp_dir) / "CLAUDE.md"
             self.assertTrue(claude_md.exists())
             text = claude_md.read_text(encoding="utf-8")
+            self.assertTrue(text.startswith("# CLAUDE.md\n\n"))
             self.assertIn("@AGENTS.md", text)
             self.assertIn("<!-- playbook:claude:start -->", text)
 
@@ -665,6 +666,39 @@ project_name = "Demo"
             self.assertIn("@AGENT_RULES.md", text)
             self.assertEqual(text.count("<!-- playbook:claude:start -->"), 1)
 
+    def test_sync_claude_md_adds_heading_to_generated_block(self):
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            claude_md = Path(tmp_dir) / "CLAUDE.md"
+            claude_md.write_text(
+                "<!-- playbook:claude:start -->\n"
+                "\n"
+                "@AGENTS.md\n"
+                "@AGENT_RULES.md\n"
+                "\n"
+                "<!-- playbook:claude:end -->\n",
+                encoding="utf-8",
+            )
+
+            config_body = f"""
+[playbook]
+project_root = "{tmp_dir}"
+deploy_root = "{CUSTOM_DEPLOY_ROOT}"
+
+[sync_memory_bank]
+project_name = "Demo"
+"""
+            config_path = Path(tmp_dir) / "playbook.toml"
+            config_path.write_text(config_body, encoding="utf-8")
+
+            result = run_cli("-config", str(config_path))
+
+            self.assertEqual(result.returncode, 0)
+            text = claude_md.read_text(encoding="utf-8")
+            self.assertTrue(text.startswith("# CLAUDE.md\n\n"))
+            self.assertIn("@AGENTS.md", text)
+            self.assertIn("@AGENT_RULES.md", text)
+            self.assertEqual(text.count("<!-- playbook:claude:start -->"), 1)
+
     def test_sync_claude_md_skips_when_already_references_agents(self):
         with tempfile.TemporaryDirectory() as tmp_dir:
             claude_md = Path(tmp_dir) / "CLAUDE.md"