diff --git a/.github/workflows/test-security.yml b/.github/workflows/test-security.yml
index 581429b4c..72f926310 100644
--- a/.github/workflows/test-security.yml
+++ b/.github/workflows/test-security.yml
@@ -31,7 +31,7 @@ jobs:
         run: pip install -r requirements-test.txt
 
       - name: <Test> Check Python dependency security
-        run: safety check -r requirements.txt -r requirements-dev.txt -r requirements-test.txt -r requirements-build.txt -r requirements-license.txt -o bare
+        run: safety check -r requirements.txt -r requirements-test.txt -r requirements-build.txt -r requirements-license.txt -o bare
 
       - name: <Deploy> Notify Discord of security testing result
         uses: sarisia/actions-status-discord@v1
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 47784d821..085f1bbcd 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -40,13 +40,11 @@ jobs:
       - name: <Test> Check dependency lists
         run: |
           poetry export --without-hashes -o requirements.txt.check
-          poetry export --without-hashes --with dev -o requirements-dev.txt.check
           poetry export --without-hashes --with test -o requirements-test.txt.check
           poetry export --without-hashes --with build -o requirements-build.txt.check
           poetry export --without-hashes --with license -o requirements-license.txt.check
 
           diff -q requirements.txt requirements.txt.check || \
-          diff -q requirements-dev.txt requirements-dev.txt.check || \
           diff -q requirements-test.txt requirements-test.txt.check || \
           diff -q requirements-build.txt requirements-build.txt.check || \
           diff -q requirements-license.txt requirements-license.txt.check > /dev/null
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index d53860eaf..c1e5784f7 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -22,12 +22,6 @@ repos:
         language: python
         stages: [push]
         pass_filenames: false
-      - id: poetry-export-dev
-        name: poetry-export-dev
-        entry: poetry export --without-hashes --with dev -o requirements-dev.txt
-        language: python
-        stages: [push]
-        pass_filenames: false
       - id: poetry-export-test
         name: poetry-export-test
         entry: poetry export --without-hashes --with test -o requirements-test.txt
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index b795696bd..855354b11 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -40,7 +40,7 @@ cd ./voicevox_engine
 git switch -c "<your_branch_name>"
 
 # 実行・開発・テスト環境のインストール
-python -m pip install -r requirements.txt -r requirements-dev.txt -r requirements-test.txt -r requirements-build.txt
+python -m pip install -r requirements.txt -r requirements-test.txt -r requirements-build.txt
 ```
 
 <!-- このプロジェクトでは
@@ -217,7 +217,6 @@ requirements.txt の更新
 
 ```bash
 poetry export --without-hashes -o requirements.txt # こちらを更新する場合は下３つも更新する必要があります。
-poetry export --without-hashes --with dev -o requirements-dev.txt
 poetry export --without-hashes --with test -o requirements-test.txt
 poetry export --without-hashes --with build -o requirements-build.txt
 poetry export --without-hashes --with license -o requirements-license.txt
@@ -237,7 +236,7 @@ poetry export --without-hashes --with license -o requirements-license.txt
 以下のコマンドにより脆弱性を診断できます：  
 
 ```bash
-safety check -r requirements.txt -r requirements-dev.txt -r requirements-test.txt -r requirements-build.txt -r requirements-license.txt
+safety check -r requirements.txt -r requirements-test.txt -r requirements-build.txt -r requirements-license.txt
 ```
 
 ### API ドキュメントの確認
diff --git a/README.md b/README.md
index 9a946170d..245e8d5ed 100644
--- a/README.md
+++ b/README.md
@@ -461,7 +461,7 @@ Issue 側で取り組み始めたことを伝えるか、最初に Draft プル
 python -m pip install -r requirements.txt
 
 # 開発環境・テスト環境・ビルド環境のインストール
-python -m pip install -r requirements-dev.txt -r requirements-test.txt -r requirements-build.txt
+python -m pip install -r requirements-test.txt -r requirements-build.txt
 ```
 
 ### 実行
@@ -650,7 +650,6 @@ poetry update # 全部更新
 
 # requirements.txtの更新
 poetry export --without-hashes -o requirements.txt # こちらを更新する場合は下３つも更新する必要があります。
-poetry export --without-hashes --with dev -o requirements-dev.txt
 poetry export --without-hashes --with test -o requirements-test.txt
 poetry export --without-hashes --with build -o requirements-build.txt
 poetry export --without-hashes --with license -o requirements-license.txt
diff --git a/poetry.lock b/poetry.lock
index 3e2451975..fc93c6753 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -2680,4 +2680,4 @@ testing = ["big-O", "jaraco.functools", "jaraco.itertools", "more-itertools", "p
 [metadata]
 lock-version = "2.0"
 python-versions = "~3.11"
-content-hash = "7bd8efa7afdf20998e2e976551a95ea21d46f9b7bdc6eb8ff1b6073b7151cd1b"
+content-hash = "23ee77179cc98cf60a8a1e4e53014d90cc319cfd3c9fcce4ab98d1c556a14ce7"
diff --git a/pyproject.toml b/pyproject.toml
index b3f03cca0..7d26d4038 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -56,11 +56,6 @@ soxr = "^0.3.6"
 pydantic = "^1.10.15"
 starlette = "^0.37.0"
 
-[tool.poetry.group.dev.dependencies]
-pre-commit = "^2.16.0"
-poetry = "1.8.2"
-poetry-plugin-export = "^1.8.0"
-
 [tool.poetry.group.test.dependencies]
 pysen = "^0.11.0"
 black = "^24.4.0"
@@ -76,6 +71,7 @@ httpx = "^0.27.0" # NOTE: required by fastapi.testclient.TestClient
 syrupy = "^4.6.1"
 types-pyyaml = "^6.0.12"
 safety = "^3.1.0"
+pre-commit = "^2.16.0"
 
 [tool.poetry.group.build.dependencies]
 pyinstaller = "^5.13"
diff --git a/requirements-dev.txt b/requirements-dev.txt
deleted file mode 100644
index 6ceb8a304..000000000
--- a/requirements-dev.txt
+++ /dev/null
@@ -1,70 +0,0 @@
-anyio==4.3.0 ; python_version >= "3.11" and python_version < "3.12"
-build==1.2.1 ; python_version >= "3.11" and python_version < "3.12"
-cachecontrol[filecache]==0.14.0 ; python_version >= "3.11" and python_version < "3.12"
-certifi==2024.2.2 ; python_version >= "3.11" and python_version < "3.12"
-cffi==1.16.0 ; python_version >= "3.11" and python_version < "3.12"
-cfgv==3.4.0 ; python_version >= "3.11" and python_version < "3.12"
-charset-normalizer==3.3.2 ; python_version >= "3.11" and python_version < "3.12"
-cleo==2.1.0 ; python_version >= "3.11" and python_version < "3.12"
-click==8.1.7 ; python_version >= "3.11" and python_version < "3.12"
-colorama==0.4.6 ; python_version >= "3.11" and python_version < "3.12" and (platform_system == "Windows" or os_name == "nt")
-crashtest==0.4.1 ; python_version >= "3.11" and python_version < "3.12"
-cryptography==42.0.7 ; python_version >= "3.11" and python_version < "3.12" and sys_platform == "linux"
-cython==3.0.10 ; python_version >= "3.11" and python_version < "3.12"
-distlib==0.3.8 ; python_version >= "3.11" and python_version < "3.12"
-dulwich==0.21.7 ; python_version >= "3.11" and python_version < "3.12"
-fastapi-slim==0.111.0 ; python_version >= "3.11" and python_version < "3.12"
-fastjsonschema==2.19.1 ; python_version >= "3.11" and python_version < "3.12"
-filelock==3.14.0 ; python_version >= "3.11" and python_version < "3.12"
-h11==0.14.0 ; python_version >= "3.11" and python_version < "3.12"
-identify==2.5.36 ; python_version >= "3.11" and python_version < "3.12"
-idna==3.7 ; python_version >= "3.11" and python_version < "3.12"
-importlib-metadata==7.1.0 ; python_version >= "3.11" and python_version < "3.12"
-installer==0.7.0 ; python_version >= "3.11" and python_version < "3.12"
-jaraco-classes==3.4.0 ; python_version >= "3.11" and python_version < "3.12"
-jeepney==0.8.0 ; python_version >= "3.11" and python_version < "3.12" and sys_platform == "linux"
-jinja2==3.1.4 ; python_version >= "3.11" and python_version < "3.12"
-keyring==24.3.1 ; python_version >= "3.11" and python_version < "3.12"
-markupsafe==2.1.5 ; python_version >= "3.11" and python_version < "3.12"
-more-itertools==10.2.0 ; python_version >= "3.11" and python_version < "3.12"
-msgpack==1.0.8 ; python_version >= "3.11" and python_version < "3.12"
-nodeenv==1.8.0 ; python_version >= "3.11" and python_version < "3.12"
-numpy==1.26.4 ; python_version >= "3.11" and python_version < "3.12"
-packaging==24.0 ; python_version >= "3.11" and python_version < "3.12"
-pexpect==4.9.0 ; python_version >= "3.11" and python_version < "3.12"
-pkginfo==1.10.0 ; python_version >= "3.11" and python_version < "3.12"
-platformdirs==4.2.2 ; python_version >= "3.11" and python_version < "3.12"
-poetry-core==1.9.0 ; python_version >= "3.11" and python_version < "3.12"
-poetry-plugin-export==1.8.0 ; python_version >= "3.11" and python_version < "3.12"
-poetry==1.8.2 ; python_version >= "3.11" and python_version < "3.12"
-pre-commit==2.21.0 ; python_version >= "3.11" and python_version < "3.12"
-ptyprocess==0.7.0 ; python_version >= "3.11" and python_version < "3.12"
-pycparser==2.22 ; python_version >= "3.11" and python_version < "3.12"
-pydantic==1.10.15 ; python_version >= "3.11" and python_version < "3.12"
-pyopenjtalk @ git+https://github.com/VOICEVOX/pyopenjtalk@b35fc89fe42948a28e33aed886ea145a51113f88 ; python_version >= "3.11" and python_version < "3.12"
-pyproject-hooks==1.1.0 ; python_version >= "3.11" and python_version < "3.12"
-python-multipart==0.0.9 ; python_version >= "3.11" and python_version < "3.12"
-pywin32-ctypes==0.2.2 ; python_version >= "3.11" and python_version < "3.12" and sys_platform == "win32"
-pyworld==0.3.4 ; python_version >= "3.11" and python_version < "3.12"
-pyyaml==6.0.1 ; python_version >= "3.11" and python_version < "3.12"
-rapidfuzz==3.9.0 ; python_version >= "3.11" and python_version < "3.12"
-requests-toolbelt==1.0.0 ; python_version >= "3.11" and python_version < "3.12"
-requests==2.31.0 ; python_version >= "3.11" and python_version < "3.12"
-secretstorage==3.3.3 ; python_version >= "3.11" and python_version < "3.12" and sys_platform == "linux"
-semver==3.0.2 ; python_version >= "3.11" and python_version < "3.12"
-setuptools==69.5.1 ; python_version >= "3.11" and python_version < "3.12"
-shellingham==1.5.4 ; python_version >= "3.11" and python_version < "3.12"
-six==1.16.0 ; python_version >= "3.11" and python_version < "3.12"
-sniffio==1.3.1 ; python_version >= "3.11" and python_version < "3.12"
-soundfile==0.12.1 ; python_version >= "3.11" and python_version < "3.12"
-soxr==0.3.7 ; python_version >= "3.11" and python_version < "3.12"
-starlette==0.37.2 ; python_version >= "3.11" and python_version < "3.12"
-tomlkit==0.12.5 ; python_version >= "3.11" and python_version < "3.12"
-tqdm==4.66.4 ; python_version >= "3.11" and python_version < "3.12"
-trove-classifiers==2024.4.10 ; python_version >= "3.11" and python_version < "3.12"
-typing-extensions==4.11.0 ; python_version >= "3.11" and python_version < "3.12"
-urllib3==2.2.1 ; python_version >= "3.11" and python_version < "3.12"
-uvicorn==0.29.0 ; python_version >= "3.11" and python_version < "3.12"
-virtualenv==20.26.2 ; python_version >= "3.11" and python_version < "3.12"
-xattr==1.1.0 ; python_version >= "3.11" and python_version < "3.12" and sys_platform == "darwin"
-zipp==3.18.1 ; python_version >= "3.11" and python_version < "3.12"
diff --git a/requirements-test.txt b/requirements-test.txt
index d60bdf090..51895ee43 100644
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -6,6 +6,7 @@ build==1.2.1 ; python_version >= "3.11" and python_version < "3.12"
 cachecontrol[filecache]==0.14.0 ; python_version >= "3.11" and python_version < "3.12"
 certifi==2024.2.2 ; python_version >= "3.11" and python_version < "3.12"
 cffi==1.16.0 ; python_version >= "3.11" and python_version < "3.12"
+cfgv==3.4.0 ; python_version >= "3.11" and python_version < "3.12"
 charset-normalizer==3.3.2 ; python_version >= "3.11" and python_version < "3.12"
 cleo==2.1.0 ; python_version >= "3.11" and python_version < "3.12"
 click==8.1.7 ; python_version >= "3.11" and python_version < "3.12"
@@ -31,6 +32,7 @@ gitpython==3.1.43 ; python_version >= "3.11" and python_version < "3.12"
 h11==0.14.0 ; python_version >= "3.11" and python_version < "3.12"
 httpcore==1.0.5 ; python_version >= "3.11" and python_version < "3.12"
 httpx==0.27.0 ; python_version >= "3.11" and python_version < "3.12"
+identify==2.5.36 ; python_version >= "3.11" and python_version < "3.12"
 idna==3.7 ; python_version >= "3.11" and python_version < "3.12"
 importlib-metadata==7.1.0 ; python_version >= "3.11" and python_version < "3.12"
 iniconfig==2.0.0 ; python_version >= "3.11" and python_version < "3.12"
@@ -49,6 +51,7 @@ more-itertools==10.2.0 ; python_version >= "3.11" and python_version < "3.12"
 msgpack==1.0.8 ; python_version >= "3.11" and python_version < "3.12"
 mypy-extensions==1.0.0 ; python_version >= "3.11" and python_version < "3.12"
 mypy==1.10.0 ; python_version >= "3.11" and python_version < "3.12"
+nodeenv==1.8.0 ; python_version >= "3.11" and python_version < "3.12"
 numpy==1.26.4 ; python_version >= "3.11" and python_version < "3.12"
 packaging==24.0 ; python_version >= "3.11" and python_version < "3.12"
 pathspec==0.12.1 ; python_version >= "3.11" and python_version < "3.12"
@@ -59,6 +62,7 @@ pluggy==1.5.0 ; python_version >= "3.11" and python_version < "3.12"
 poetry-core==1.9.0 ; python_version >= "3.11" and python_version < "3.12"
 poetry-plugin-export==1.8.0 ; python_version >= "3.11" and python_version < "3.12"
 poetry==1.8.2 ; python_version >= "3.11" and python_version < "3.12"
+pre-commit==2.21.0 ; python_version >= "3.11" and python_version < "3.12"
 ptyprocess==0.7.0 ; python_version >= "3.11" and python_version < "3.12"
 pycodestyle==2.11.1 ; python_version >= "3.11" and python_version < "3.12"
 pycparser==2.22 ; python_version >= "3.11" and python_version < "3.12"