diff --git a/src/takopi/settings.py b/src/takopi/settings.py
index 2328199..f20f933 100644
--- a/src/takopi/settings.py
+++ b/src/takopi/settings.py
@@ -5,6 +5,7 @@ from typing import Annotated, Any, ClassVar, Literal
 from collections.abc import Iterable
 
 from pydantic import (
+    BeforeValidator,
     BaseModel,
     ConfigDict,
     Field,
@@ -53,6 +54,15 @@ def _normalize_project_path(value: str, *, config_path: Path) -> Path:
     return path
 
 
+def _coerce_chat_id(value: Any) -> Any:
+    if isinstance(value, str):
+        return int(value.strip())
+    return value
+
+
+ChatId = Annotated[StrictInt, BeforeValidator(_coerce_chat_id)]
+
+
 class TelegramTopicsSettings(BaseModel):
     model_config = ConfigDict(extra="forbid", str_strip_whitespace=True)
 
@@ -93,7 +103,7 @@ class TelegramTransportSettings(BaseModel):
     model_config = ConfigDict(extra="forbid", str_strip_whitespace=True)
 
     bot_token: NonEmptyStr
-    chat_id: StrictInt
+    chat_id: ChatId
     allowed_user_ids: list[StrictInt] = Field(default_factory=list)
     message_overflow: Literal["trim", "split"] = "trim"
     voice_transcription: bool = False
@@ -128,7 +138,7 @@ class ProjectSettings(BaseModel):
     worktrees_dir: NonEmptyStr = ".worktrees"
     default_engine: NonEmptyStr | None = None
     worktree_base: NonEmptyStr | None = None
-    chat_id: StrictInt | None = None
+    chat_id: ChatId | None = None
 
 
 class TakopiSettings(BaseSettings):
diff --git a/tests/test_exec_bridge.py b/tests/test_exec_bridge.py
index 32ff833..c793c25 100644
--- a/tests/test_exec_bridge.py
+++ b/tests/test_exec_bridge.py
@@ -92,8 +92,8 @@ def test_require_telegram_rejects_empty_token(tmp_path) -> None:
         require_telegram(settings, config_path)
 
 
-def test_load_settings_rejects_string_chat_id(tmp_path) -> None:
-    from takopi.config import ConfigError
+def test_load_settings_accepts_string_chat_id(tmp_path) -> None:
+    from takopi.settings import require_telegram
 
     config_path = tmp_path / "takopi.toml"
     config_path.write_text(
@@ -102,8 +102,9 @@ def test_load_settings_rejects_string_chat_id(tmp_path) -> None:
         encoding="utf-8",
     )
 
-    with pytest.raises(ConfigError, match="chat_id"):
-        load_settings(config_path)
+    settings, _ = load_settings(config_path)
+    _, chat_id = require_telegram(settings, config_path)
+    assert chat_id == 123
 
 
 def test_codex_extract_resume_finds_command() -> None:
diff --git a/tests/test_projects_config.py b/tests/test_projects_config.py
index d708315..f9d69d1 100644
--- a/tests/test_projects_config.py
+++ b/tests/test_projects_config.py
@@ -130,6 +130,22 @@ def test_projects_chat_id_must_be_unique() -> None:
         )
 
 
+def test_projects_string_chat_id_is_coerced() -> None:
+    config = {
+        "transports": {"telegram": {"bot_token": "token", "chat_id": 123}},
+        "projects": {"z80": {"path": "/tmp/repo", "chat_id": "-10"}},
+    }
+    settings = TakopiSettings.model_validate(config)
+    projects = settings.to_projects_config(
+        config_path=Path("takopi.toml"),
+        engine_ids=["codex"],
+        reserved=RESERVED_CHAT_COMMANDS,
+    )
+
+    assert projects.projects["z80"].chat_id == -10
+    assert projects.chat_map[-10] == "z80"
+
+
 def test_projects_relative_path_resolves(tmp_path: Path) -> None:
     config_path = tmp_path / "takopi.toml"
     settings = TakopiSettings.model_validate(
diff --git a/tests/test_settings_contract.py b/tests/test_settings_contract.py
index c303ade..01bd3fb 100644
--- a/tests/test_settings_contract.py
+++ b/tests/test_settings_contract.py
@@ -28,3 +28,13 @@ def test_settings_rejects_bool_chat_id(tmp_path: Path) -> None:
 
     with pytest.raises(ConfigError, match="chat_id"):
         validate_settings_data(data, config_path=tmp_path / "takopi.toml")
+
+
+def test_settings_rejects_float_chat_id(tmp_path: Path) -> None:
+    data = {
+        "transport": "telegram",
+        "transports": {"telegram": {"bot_token": "token", "chat_id": 123.0}},
+    }
+
+    with pytest.raises(ConfigError, match="chat_id"):
+        validate_settings_data(data, config_path=tmp_path / "takopi.toml")