diff --git a/mito_train/training/train_board_ocr.py b/mito_train/training/train_board_ocr.py
index 07b8385..5f9539f 100644
--- a/mito_train/training/train_board_ocr.py
+++ b/mito_train/training/train_board_ocr.py
@@ -510,7 +510,9 @@ def log_main(msg: str) -> None:
 def main() -> None:
     # Pull HF_TOKEN / WANDB_API_KEY / CF_* out of .env into os.environ before
     # any HF or wandb call resolves credentials. No-op if .env is missing.
-    load_dotenv()
+    # override=True so devcontainer.json's ${localEnv:...} forwards that expand
+    # to an empty string on hosts without those vars don't win over .env.
+    load_dotenv(override=True)
     p = argparse.ArgumentParser()
     p.add_argument("--mode", choices=["smoke", "full"], default="smoke")
     p.add_argument("--backbone", default="mobilenet_v3_small",
diff --git a/mito_train/training/train_detector.py b/mito_train/training/train_detector.py
index cd0d953..c539c14 100644
--- a/mito_train/training/train_detector.py
+++ b/mito_train/training/train_detector.py
@@ -78,7 +78,9 @@ def evaluate(model: nn.Module, loader: DataLoader, device: str) -> dict[str, flo
 def main() -> None:
     # Pull HF_TOKEN / WANDB_API_KEY / CF_* out of .env into os.environ before
     # any wandb or HF call resolves credentials. No-op if .env is missing.
-    load_dotenv()
+    # override=True so devcontainer.json's ${localEnv:...} forwards that expand
+    # to an empty string on hosts without those vars don't win over .env.
+    load_dotenv(override=True)
     p = argparse.ArgumentParser()
     p.add_argument("--train-manifest", type=Path, default=Path("data/detector/train.jsonl"))
     p.add_argument("--val-manifest", type=Path, default=Path("data/detector/val.jsonl"))
diff --git a/mito_train/training/train_piece.py b/mito_train/training/train_piece.py
index dd6a5b7..a94013e 100644
--- a/mito_train/training/train_piece.py
+++ b/mito_train/training/train_piece.py
@@ -223,7 +223,9 @@ def run_manifest(args: argparse.Namespace) -> None:
 def main() -> None:
     # Pull WANDB_API_KEY / CF_* / HF_TOKEN out of .env into os.environ before
     # any wandb or HF call resolves credentials. No-op if .env is missing.
-    load_dotenv()
+    # override=True so devcontainer.json's ${localEnv:...} forwards that expand
+    # to an empty string on hosts without those vars don't win over .env.
+    load_dotenv(override=True)
     p = argparse.ArgumentParser()
     p.add_argument("--mode", choices=["smoke", "manifest"], default="smoke")
     # smoke-mode args
diff --git a/pyproject.toml b/pyproject.toml
index 054dfcf..682df05 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "mito-train"
-version = "0.3.1"
+version = "0.3.2"
 description = "ぴよ将棋OCR 3モデル (board-detector / piece-classifier / hand-classifier) の学習・ONNX出力"
 requires-python = ">=3.11"
 dependencies = [
diff --git a/uv.lock b/uv.lock
index ac793db..1b87464 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1119,7 +1119,7 @@ wheels = [
 
 [[package]]
 name = "mito-train"
-version = "0.3.1"
+version = "0.3.2"
 source = { editable = "." }
 dependencies = [
     { name = "albumentations" },