diff --git a/src/storymachine/config.py b/src/storymachine/config.py
index ad604bb..17c0ef1 100644
--- a/src/storymachine/config.py
+++ b/src/storymachine/config.py
@@ -7,7 +7,7 @@ class Settings(BaseSettings):
     openai_api_key: str = Field(..., frozen=True, alias="OPENAI_API_KEY")
     github_token: str | None = Field(None, frozen=True, alias="GITHUB_TOKEN")
     gitlab_token: str | None = Field(None, frozen=True, alias="GITLAB_TOKEN")
-    model: str = Field("gpt-5", alias="MODEL")
+    model: str = Field("gpt-5.1", alias="MODEL")
     reasoning_effort: str = Field("low", alias="REASONING_EFFORT")
 
     class Config:
diff --git a/tests/test_config.py b/tests/test_config.py
index f56e420..d2cb40c 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -139,7 +139,7 @@ def test_settings_default_model(self, monkeypatch, tmp_path: Path) -> None:
             os.chdir(tmp_path)
             settings = Settings()  # pyright: ignore[reportCallIssue]
 
-            assert settings.model == "gpt-5"
+            assert settings.model == "gpt-5.1"
         finally:
             os.chdir(original_cwd)