diff --git a/pyproject.toml b/pyproject.toml
index 5995fc9..9e68d6d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,7 +19,6 @@ classifiers = [
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
-    "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: Implementation :: CPython",
 ]
 dependencies = [
@@ -37,7 +36,7 @@ dependencies = [
     'pydantic',
     'pyopenjtalk-dict',
     'pypinyin',
-    'pyworld',
+    # 'pyworld',
     'safetensors',
     'scipy',
     'torch>=2.1,<2.2',
@@ -74,7 +73,7 @@ cov = [
 ]
 
 [[tool.hatch.envs.test.matrix]]
-python = ["3.9", "3.10", "3.11", "3.12"]
+python = ["3.9", "3.10", "3.11"]
 
 [tool.coverage.run]
 source_pkgs = ["style_bert_vits2", "tests"]
diff --git a/style_bert_vits2/models/utils/__init__.py b/style_bert_vits2/models/utils/__init__.py
index 51e19d9..e0d922f 100644
--- a/style_bert_vits2/models/utils/__init__.py
+++ b/style_bert_vits2/models/utils/__init__.py
@@ -4,24 +4,27 @@ import os
 import re
 import subprocess
 from pathlib import Path
-from typing import Any, Optional, Union
+from typing import Any, Optional, Union, TYPE_CHECKING
 
 import numpy as np
 import torch
 from numpy.typing import NDArray
 from scipy.io.wavfile import read
-from torch.utils.tensorboard import SummaryWriter
 
 from style_bert_vits2.logging import logger
 from style_bert_vits2.models.utils import checkpoints  # type: ignore
 from style_bert_vits2.models.utils import safetensors  # type: ignore
 
+if TYPE_CHECKING:
+    # tensorboard はライブラリとしてインストールされている場合は依存関係に含まれないため、型チェック時のみインポートする
+    from torch.utils.tensorboard import SummaryWriter
+
 
 __is_matplotlib_imported = False
 
 
 def summarize(
-    writer: SummaryWriter,
+    writer: "SummaryWriter",
     global_step: int,
     scalars: dict[str, float] = {},
     histograms: dict[str, Any] = {},