diff --git a/.coveragerc b/.coveragerc
deleted file mode 100644
index 26e44f99..00000000
--- a/.coveragerc
+++ /dev/null
@@ -1,3 +0,0 @@
-[run]
-concurrency = multiprocessing,thread
-source = optuna_dashboard/
diff --git a/.github/workflows/python-coverage.yml b/.github/workflows/python-coverage.yml
deleted file mode 100644
index 729c6f65..00000000
--- a/.github/workflows/python-coverage.yml
+++ /dev/null
@@ -1,44 +0,0 @@
-name: python coverage
-
-on:
-  push:
-    branches:
-      - master
-  pull_request: {}
-
-jobs:
-  coverage:
-    runs-on: ubuntu-latest
-    steps:
-    - name: Checkout
-      uses: actions/checkout@v3
-
-    - name: Setup Python
-      uses: actions/setup-python@v4
-      with:
-        python-version: '3.10'
-        architecture: x64
-
-    - name: Install dependencies
-      run: |
-        python -m pip install --progress-bar off --upgrade pip setuptools
-        pip install --progress-bar off .[optional]
-        pip install --progress-bar off .[test]
-        pip install --progress-bar off "optuna>=3.0.0"
-        pip install --progress-bar off .
-        echo 'import coverage; coverage.process_startup()' > sitecustomize.py
-
-    - name: Tests
-      env:
-        PYTHONPATH: .  # To invoke sitecutomize.py
-        COVERAGE_PROCESS_START: .coveragerc  # https://coverage.readthedocs.io/en/6.4.1/subprocess.html
-        COVERAGE_COVERAGE: yes  # https://github.com/nedbat/coveragepy/blob/65bf33fc03209ffb01bbbc0d900017614645ee7a/coverage/control.py#L255-L261
-      run: |
-        coverage run --source=optuna_dashboard -m pytest python_tests
-        coverage combine
-        coverage xml
-
-    - name: Upload coverage to Codecov
-      uses: codecov/codecov-action@v3
-      with:
-        file: ./coverage.xml
diff --git a/.github/workflows/python-tests.yml b/.github/workflows/python-tests.yml
index 8fee4e44..612ddb59 100644
--- a/.github/workflows/python-tests.yml
+++ b/.github/workflows/python-tests.yml
@@ -45,8 +45,7 @@ jobs:
         # python_tests requires optuna>=3.0.0 since it imports FloatDistribution
         run: |
           python -m pip install --progress-bar off --upgrade pip setuptools
-          pip install --progress-bar off .[optional]
-          pip install --progress-bar off .[test]
+          pip install streamlit boto3 moto[s3] pytest
           pip install --progress-bar off "optuna>=3.0.0"
           pip install --progress-bar off .
       - run: pytest python_tests
@@ -62,8 +61,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --progress-bar off --upgrade pip setuptools
-          pip install --progress-bar off .[optional]
-          pip install --progress-bar off .[test]
+          pip install streamlit boto3 moto[s3] pytest
           pip install --progress-bar off .
           python -m pip install --progress-bar off --upgrade git+https://github.com/optuna/optuna.git
       - run: pytest python_tests
diff --git a/.gitignore b/.gitignore
index d530dc27..dde468fc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -28,11 +28,6 @@ docs/_generated/
 rustlib/target/
 rustlib/pkg/
 
-# Test
-.coverage
-.coverage.*
-coverage.xml
-
 # Others
 .envrc
 .idea/
diff --git a/pyproject.toml b/pyproject.toml
index b65597b0..be4a18e0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,18 +33,6 @@ dependencies = [
 ]
 dynamic = ["version"]
 
-[project.optional-dependencies]
-test = [
-    "coverage",
-    "pytest",
-    "moto[s3]",
-]
-
-optional = [
-    "streamlit",
-    "boto3",
-]
-
 [project.scripts]
 optuna-dashboard = "optuna_dashboard._cli:main"