diff --git a/.github/workflows/benchmarks.yml b/.github/workflows/benchmarks.yml
index 4baabc8..1ff6492 100644
--- a/.github/workflows/benchmarks.yml
+++ b/.github/workflows/benchmarks.yml
@@ -6,6 +6,7 @@ on:
     - 'cmaes/**.py'
     - 'benchmark/*.py'
     - 'benchmark/runner.sh'
+    - 'requirements-bench.txt'
 jobs:
   benchmark-six-hump-camel:
     name: Run kurobako benchmark
@@ -19,7 +20,7 @@ jobs:
           architecture: 'x64'
       - run: pip install -U pip setuptools
       - run: python setup.py develop
-      - run: pip install --progress-bar off -e '.[benchmark]'
+      - run: pip install --progress-bar off -r requirements-bench.txt
       - run: pip install --progress-bar off -U git+https://github.com/sile/kurobako-py
       - run: pip install --progress-bar off -U git+https://github.com/optuna/optuna.git
       - name: Cache kurobako CLI
@@ -111,7 +112,7 @@ jobs:
           architecture: 'x64'
       - run: pip install -U pip setuptools
       - run: python setup.py develop
-      - run: pip install --progress-bar off -e '.[benchmark]'
+      - run: pip install --progress-bar off -r requirements-bench.txt
       - run: pip install --progress-bar off -U git+https://github.com/sile/kurobako-py
       - run: pip install --progress-bar off -U git+https://github.com/optuna/optuna.git
       - name: Cache kurobako CLI
diff --git a/.github/workflows/examples.yml b/.github/workflows/examples.yml
index 55d1ae6..dfbc8e7 100644
--- a/.github/workflows/examples.yml
+++ b/.github/workflows/examples.yml
@@ -23,7 +23,7 @@ jobs:
       - name: Install dependencies
         run: |
           pip install -U pip setuptools
-          pip install --progress-bar off optuna
+          pip install --progress-bar off optuna 'numpy<1.20.0'
           pip install --progress-bar off -U .
       - run: python examples/quadratic_function.py
       - run: python examples/ipop_cmaes.py
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 8dfd804..d95da2d 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -18,8 +18,8 @@ jobs:
           architecture: x64
       - name: Install dependencies
         run: |
-          python -m pip install --upgrade pip setuptools
-          pip install --progress-bar off .[lint]
+          python -m pip install --upgrade pip setuptools 'numpy<1.20.0'
+          pip install --progress-bar off -r requirements-dev.txt
       - run: flake8 . --show-source --statistics
       - run: black --check .
       - run: mypy cmaes
@@ -37,6 +37,6 @@ jobs:
           architecture: x64
       - name: Install dependencies
         run: |
-          python -m pip install --upgrade pip setuptools
+          python -m pip install --upgrade pip setuptools 'numpy<1.20.0'
           pip install --progress-bar off .
       - run: python -m unittest
diff --git a/requirements-bench.txt b/requirements-bench.txt
new file mode 100644
index 0000000..c28302c
--- /dev/null
+++ b/requirements-bench.txt
@@ -0,0 +1,3 @@
+kurobako
+cma
+optuna
diff --git a/requirements-dev.txt b/requirements-dev.txt
new file mode 100644
index 0000000..b3fa561
--- /dev/null
+++ b/requirements-dev.txt
@@ -0,0 +1,15 @@
+# install_requires
+numpy<1.20.0
+
+# visualization
+matplotlib
+scipy
+
+# lint
+mypy
+flake8
+black
+
+# release
+wheel
+twine
diff --git a/setup.cfg b/setup.cfg
index e9a1b12..33b0a4e 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -32,22 +32,6 @@ setup_requires =
 install_requires =
     numpy
 
-[options.extras_require]
-benchmark =
-    kurobako
-    cma
-    optuna
-visualization =
-    matplotlib
-    scipy
-lint =
-    mypy
-    flake8
-    black
-release =
-    wheel
-    twine
-
 [options.packages.find]
 exclude =
     tests