diff --git a/datamodel_code_generator/__main__.py b/datamodel_code_generator/__main__.py
index 03c4e241b..458e0a42b 100644
--- a/datamodel_code_generator/__main__.py
+++ b/datamodel_code_generator/__main__.py
@@ -53,7 +53,6 @@
 from datamodel_code_generator.format import (
     DatetimeClassType,
     PythonVersion,
-    black_find_project_root,
     is_supported_in_black,
 )
 from datamodel_code_generator.parser import LiteralType
@@ -366,6 +365,26 @@ def merge_args(self, args: Namespace) -> None:
             setattr(self, field_name, getattr(parsed_args, field_name))
 
 
+def _get_pyproject_toml_config(source: Path) -> Optional[Dict[str, Any]]:
+    """Find and return the [tool.datamodel-codgen] section of the closest
+    pyproject.toml if it exists.
+    """
+
+    current_path = source
+    while current_path != current_path.parent:
+        if (current_path / 'pyproject.toml').is_file():
+            pyproject_toml = load_toml(current_path / 'pyproject.toml')
+            if 'datamodel-codegen' in pyproject_toml.get('tool', {}):
+                return pyproject_toml['tool']['datamodel-codegen']
+
+        if (current_path / '.git').exists():
+            # Stop early if we see a git repository root.
+            return None
+
+        current_path = current_path.parent
+    return None
+
+
 def main(args: Optional[Sequence[str]] = None) -> Exit:
     """Main function."""
 
@@ -383,16 +402,9 @@ def main(args: Optional[Sequence[str]] = None) -> Exit:
         print(version)
         exit(0)
 
-    root = black_find_project_root((Path().resolve(),))
-    pyproject_toml_path = root / 'pyproject.toml'
-    if pyproject_toml_path.is_file():
-        pyproject_toml: Dict[str, Any] = {
-            k.replace('-', '_'): v
-            for k, v in load_toml(pyproject_toml_path)
-            .get('tool', {})
-            .get('datamodel-codegen', {})
-            .items()
-        }
+    pyproject_config = _get_pyproject_toml_config(Path().resolve())
+    if pyproject_config is not None:
+        pyproject_toml = {k.replace('-', '_'): v for k, v in pyproject_config.items()}
     else:
         pyproject_toml = {}
 
diff --git a/tests/data/expected/main_kr/pyproject/output.strictstr.py b/tests/data/expected/main_kr/pyproject/output.strictstr.py
new file mode 100644
index 000000000..8ddb3f3e4
--- /dev/null
+++ b/tests/data/expected/main_kr/pyproject/output.strictstr.py
@@ -0,0 +1,69 @@
+# generated by datamodel-codegen:
+#   filename:  api.yaml
+#   timestamp: 2019-07-26T00:00:00+00:00
+
+from __future__ import annotations
+
+from typing import List, Optional
+
+from pydantic import AnyUrl, BaseModel, Field, StrictStr
+
+
+class Pet(BaseModel):
+    id: int
+    name: StrictStr
+    tag: Optional[StrictStr] = None
+
+
+class Pets(BaseModel):
+    __root__: List[Pet]
+
+
+class User(BaseModel):
+    id: int
+    name: StrictStr
+    tag: Optional[StrictStr] = None
+
+
+class Users(BaseModel):
+    __root__: List[User]
+
+
+class Id(BaseModel):
+    __root__: StrictStr
+
+
+class Rules(BaseModel):
+    __root__: List[StrictStr]
+
+
+class Error(BaseModel):
+    code: int
+    message: StrictStr
+
+
+class Api(BaseModel):
+    apiKey: Optional[StrictStr] = Field(
+        None, description='To be used as a dataset parameter value'
+    )
+    apiVersionNumber: Optional[StrictStr] = Field(
+        None, description='To be used as a version parameter value'
+    )
+    apiUrl: Optional[AnyUrl] = Field(
+        None, description="The URL describing the dataset's fields"
+    )
+    apiDocumentationUrl: Optional[AnyUrl] = Field(
+        None, description='A URL to the API console for each API'
+    )
+
+
+class Apis(BaseModel):
+    __root__: List[Api]
+
+
+class Event(BaseModel):
+    name: Optional[StrictStr] = None
+
+
+class Result(BaseModel):
+    event: Optional[Event] = None
diff --git a/tests/test_main_kr.py b/tests/test_main_kr.py
index 13e157f04..eb32ae1dc 100644
--- a/tests/test_main_kr.py
+++ b/tests/test_main_kr.py
@@ -7,7 +7,7 @@
 import pytest
 from freezegun import freeze_time
 
-from datamodel_code_generator import inferred_message
+from datamodel_code_generator import chdir, inferred_message
 from datamodel_code_generator.__main__ import Exit, main
 
 try:
@@ -207,6 +207,46 @@ def test_pyproject():
         )
 
 
+@pytest.mark.skipif(
+    black.__version__.split('.')[0] == '19',
+    reason="Installed black doesn't support the old style",
+)
+@freeze_time('2019-07-26')
+def test_pyproject_with_tool_section():
+    """Test that a pyproject.toml with a [tool.datamodel-codegen] section is
+    found and its configuration applied.
+    """
+    with TemporaryDirectory() as output_dir:
+        output_dir = Path(output_dir)
+        pyproject_toml = """
+[tool.datamodel-codegen]
+target-python-version = "3.10"
+strict-types = ["str"]
+"""
+        with open(output_dir / 'pyproject.toml', 'w') as f:
+            f.write(pyproject_toml)
+        output_file: Path = output_dir / 'output.py'
+
+        # Run main from within the output directory so we can find our
+        # pyproject.toml.
+        with chdir(output_dir):
+            return_code: Exit = main(
+                [
+                    '--input',
+                    str((OPEN_API_DATA_PATH / 'api.yaml').resolve()),
+                    '--output',
+                    str(output_file.resolve()),
+                ]
+            )
+
+        assert return_code == Exit.OK
+        assert (
+            output_file.read_text()
+            # We expect the output to use pydantic.StrictStr in place of str
+            == (EXPECTED_MAIN_KR_PATH / 'pyproject' / 'output.strictstr.py').read_text()
+        )
+
+
 @freeze_time('2019-07-26')
 def test_main_use_schema_description():
     with TemporaryDirectory() as output_dir: