diff --git a/clpy/_version.py b/clpy/_version.py
index 1aab64cb38c..38da91ee5a4 100644
--- a/clpy/_version.py
+++ b/clpy/_version.py
@@ -1 +1 @@
-__version__ = '2.1.0rc1'
+__version__ = '2.1.0.1'
diff --git a/clpy/random/generator.py b/clpy/random/generator.py
index e16fdd80ff9..34e350c3c41 100644
--- a/clpy/random/generator.py
+++ b/clpy/random/generator.py
@@ -397,6 +397,8 @@ def get_random_state():
         seed = os.getenv('CLPY_SEED')
         if seed is None:
             seed = os.getenv('CHAINER_SEED')
+        if seed is not None:
+            seed = numpy.uint64(int(seed))
         rs = RandomState(seed)
         rs = _random_states.setdefault(dev.id, rs)
     return rs
diff --git a/docker/python2/Dockerfile b/docker/python2/Dockerfile
index 675123c8279..3d7ca934793 100644
--- a/docker/python2/Dockerfile
+++ b/docker/python2/Dockerfile
@@ -6,4 +6,4 @@ RUN apt-get update -y && \
     python-pip && \
     rm -rf /var/lib/apt/lists/* /var/cache/apt/archives/*
 
-RUN pip install cupy==2.1.0
+RUN pip install cupy==2.1.0.1
diff --git a/docker/python3/Dockerfile b/docker/python3/Dockerfile
index 474f58956a8..170ec5e1167 100644
--- a/docker/python3/Dockerfile
+++ b/docker/python3/Dockerfile
@@ -6,4 +6,4 @@ RUN apt-get update -y && \
     python3-pip && \
     rm -rf /var/lib/apt/lists/* /var/cache/apt/archives/*
 
-RUN pip3 install cupy==2.1.0
+RUN pip3 install cupy==2.1.0.1
diff --git a/tests/clpy_tests/random_tests/test_generator.py b/tests/clpy_tests/random_tests/test_generator.py
index bcbd8e89f57..b171efb2565 100644
--- a/tests/clpy_tests/random_tests/test_generator.py
+++ b/tests/clpy_tests/random_tests/test_generator.py
@@ -551,15 +551,12 @@ def test_thread_safe(self):
 class TestGetRandomState2(unittest.TestCase):
 
     def setUp(self):
-        self.rs_tmp = generator.RandomState
-        generator.RandomState = mock.Mock()
         self.rs_dict = generator._random_states
         generator._random_states = {}
         self.clpy_seed = os.getenv('CLPY_SEED')
         self.chainer_seed = os.getenv('CHAINER_SEED')
 
     def tearDown(self, *args):
-        generator.RandomState = self.rs_tmp
         generator._random_states = self.rs_dict
         if self.clpy_seed is None:
             os.environ.pop('CLPY_SEED', None)
@@ -573,26 +570,55 @@ def tearDown(self, *args):
     def test_get_random_state_no_clpy_no_chainer_seed(self):
         os.environ.pop('CLPY_SEED', None)
         os.environ.pop('CHAINER_SEED', None)
-        generator.get_random_state()
-        generator.RandomState.assert_called_with(None)
+        rvs0 = self._get_rvs_reset()
+        rvs1 = self._get_rvs_reset()
+
+        self._check_different(rvs0, rvs1)
+
+    def test_get_random_state_no_cupy_with_chainer_seed(self):
+        rvs0 = self._get_rvs(generator.RandomState(5))
 
-    def test_get_random_state_no_clpy_with_chainer_seed(self):
         os.environ.pop('CLPY_SEED', None)
         os.environ['CHAINER_SEED'] = '5'
-        generator.get_random_state()
-        generator.RandomState.assert_called_with('5')
+        rvs1 = self._get_rvs_reset()
+
+        self._check_same(rvs0, rvs1)
+
+    def test_get_random_state_with_cupy_no_chainer_seed(self):
+        rvs0 = self._get_rvs(generator.RandomState(6))
 
-    def test_get_random_state_with_clpy_no_chainer_seed(self):
         os.environ['CLPY_SEED'] = '6'
         os.environ.pop('CHAINER_SEED', None)
-        generator.get_random_state()
-        generator.RandomState.assert_called_with('6')
+        rvs1 = self._get_rvs_reset()
+
+        self._check_same(rvs0, rvs1)
+
+    def test_get_random_state_with_cupy_with_chainer_seed(self):
+        rvs0 = self._get_rvs(generator.RandomState(7))
 
-    def test_get_random_state_with_clpy_with_chainer_seed(self):
         os.environ['CLPY_SEED'] = '7'
         os.environ['CHAINER_SEED'] = '8'
-        generator.get_random_state()
-        generator.RandomState.assert_called_with('7')
+        rvs1 = self._get_rvs_reset()
+
+        self._check_same(rvs0, rvs1)
+
+    def _get_rvs(self, rs):
+        rvu = rs.rand(4)
+        rvn = rs.randn(4)
+        return rvu, rvn
+
+    def _get_rvs_reset(self):
+        generator.reset_states()
+        return self._get_rvs(generator.get_random_state())
+
+    def _check_same(self, rvs0, rvs1):
+        for rv0, rv1 in zip(rvs0, rvs1):
+            testing.assert_array_equal(rv0, rv1)
+
+    def _check_different(self, rvs0, rvs1):
+        for rv0, rv1 in zip(rvs0, rvs1):
+            for r0, r1 in zip(rv0, rv1):
+                self.assertNotEqual(r0, r1)
 
 
 class TestCheckAndGetDtype(unittest.TestCase):