diff --git a/.github/workflows/python-coverage.yml b/.github/workflows/python-coverage.yml
index d8aca48f..729c6f65 100644
--- a/.github/workflows/python-coverage.yml
+++ b/.github/workflows/python-coverage.yml
@@ -22,6 +22,7 @@ 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 --progress-bar off "optuna>=3.0.0"
         pip install --progress-bar off .
diff --git a/.github/workflows/python-tests.yml b/.github/workflows/python-tests.yml
index 1b5f9989..8fee4e44 100644
--- a/.github/workflows/python-tests.yml
+++ b/.github/workflows/python-tests.yml
@@ -45,7 +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 streamlit boto3 moto[s3]
+          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 .
@@ -62,7 +62,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --progress-bar off --upgrade pip setuptools
-          pip install streamlit boto3 moto[s3]
+          pip install --progress-bar off .[optional]
           pip install --progress-bar off .[test]
           pip install --progress-bar off .
           python -m pip install --progress-bar off --upgrade git+https://github.com/optuna/optuna.git
diff --git a/pyproject.toml b/pyproject.toml
index 93d24743..1dcb9a19 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,6 +39,12 @@ test = [
     "pytest",
 ]
 
+optional = [
+    "streamlit",
+    "boto3",
+    "moto[s3]",
+]
+
 [project.scripts]
 optuna-dashboard = "optuna_dashboard._cli:main"