diff --git a/.pfnci/hint.pbtxt b/.pfnci/hint.pbtxt
index 03b18902d7e9..3e4a42ebe2e0 100644
--- a/.pfnci/hint.pbtxt
+++ b/.pfnci/hint.pbtxt
@@ -5,6 +5,7 @@
 
 # Slow tests take 60+ seconds.
 rules { name: "chainer_tests/functions_tests/activation_tests/test_crelu.py" xdist: 4 deadline: 240 }
+rules { name: "chainer_tests/functions_tests/evaluation_tests/test_accuracy.py" xdist: 4 deadline: 240 }
 rules { name: "chainer_tests/functions_tests/loss_tests/test_softmax_cross_entropy.py" xdist: 8 deadline: 240 }
 rules { name: "chainer_tests/functions_tests/math_tests/test_sparse_matmul.py" xdist: 4 deadline: 240 }
 rules { name: "chainer_tests/functions_tests/normalization_tests/test_batch_normalization.py" xdist: 4 deadline: 240 }
@@ -55,7 +56,6 @@ rules { name: "chainer_tests/functions_tests/connection_tests/test_convolution_n
 rules { name: "chainer_tests/functions_tests/connection_tests/test_deconvolution_2d.py" }
 rules { name: "chainer_tests/functions_tests/connection_tests/test_deconvolution_nd.py" }
 rules { name: "chainer_tests/functions_tests/connection_tests/test_embed_id.py" }
-rules { name: "chainer_tests/functions_tests/evaluation_tests/test_accuracy.py" }
 rules { name: "chainer_tests/functions_tests/loss_tests/test_contrastive.py" }
 rules { name: "chainer_tests/functions_tests/loss_tests/test_negative_sampling.py" }
 rules { name: "chainer_tests/functions_tests/loss_tests/test_sigmoid_cross_entropy.py" }
diff --git a/scripts/ci/travis/steps.sh b/scripts/ci/travis/steps.sh
index 45593c1c0354..5ad8392ead7f 100644
--- a/scripts/ci/travis/steps.sh
+++ b/scripts/ci/travis/steps.sh
@@ -158,7 +158,10 @@ step_chainer_tests() {
 
 
 step_chainerx_python_tests() {
-    pytest -rfEX "$REPO_DIR"/tests/chainerx_tests
+    # TODO(niboshi): Apply pairwise parameterization only selectively. See
+    # #8210.
+    env CHAINER_TEST_PAIRWISE_PARAMETERIZE=always \
+        pytest -rfEX "$REPO_DIR"/tests/chainerx_tests
 }
 
 
diff --git a/tests/chainer_tests/conftest.py b/tests/chainer_tests/conftest.py
index 0a5a8a66385d..182fa6d96d26 100644
--- a/tests/chainer_tests/conftest.py
+++ b/tests/chainer_tests/conftest.py
@@ -1,8 +1,6 @@
 import pytest
 
 from chainer.backends import cuda
-from chainer import testing
-from chainer.testing import parameterized
 import chainerx
 
 
@@ -13,20 +11,6 @@
     pytest.mark.chainerx = pytest.mark.skip
 
 
-def pytest_collection(session):
-    # Perform pairwise testing.
-    # TODO(kataoka): This is a tentative fix. Discuss its public interface.
-    pairwise_product_dict = parameterized._pairwise_product_dict
-    testing.product_dict = pairwise_product_dict
-    parameterized.product_dict = pairwise_product_dict
-
-
-def pytest_collection_finish(session):
-    product_dict = parameterized._product_dict_orig
-    testing.product_dict = product_dict
-    parameterized.product_dict = product_dict
-
-
 def pytest_runtest_teardown(item, nextitem):
     if cuda.available:
         assert cuda.cupy.cuda.runtime.getDevice() == 0
diff --git a/tests/chainerx_tests/conftest.py b/tests/chainerx_tests/conftest.py
index 01b2c5335aa3..8cbede8e2efc 100644
--- a/tests/chainerx_tests/conftest.py
+++ b/tests/chainerx_tests/conftest.py
@@ -1,7 +1,5 @@
 import pytest
 
-from chainer import testing
-from chainer.testing import parameterized
 import chainerx.testing
 
 from chainerx_tests import cuda_utils
@@ -11,20 +9,6 @@ def pytest_configure(config):
     _register_cuda_marker(config)
 
 
-def pytest_collection(session):
-    # Perform pairwise testing.
-    # TODO(kataoka): This is a tentative fix. Discuss its public interface.
-    pairwise_product_dict = parameterized._pairwise_product_dict
-    testing.product_dict = pairwise_product_dict
-    parameterized.product_dict = pairwise_product_dict
-
-
-def pytest_collection_finish(session):
-    product_dict = parameterized._product_dict_orig
-    testing.product_dict = product_dict
-    parameterized.product_dict = product_dict
-
-
 def pytest_runtest_setup(item):
     _setup_cuda_marker(item)
 
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 000000000000..ec080fa0e6f5
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,24 @@
+import os
+
+from chainer import testing
+from chainer.testing import parameterized
+
+
+_pairwise_parameterize = os.environ.get('CHAINER_TEST_PAIRWISE_PARAMETERIZATION', 'never')
+assert _pairwise_parameterize in ('never', 'always')
+
+
+def pytest_collection(session):
+    # Perform pairwise testing.
+    # TODO(kataoka): This is a tentative fix. Discuss its public interface.
+    if _pairwise_parameterize == 'always':
+        pairwise_product_dict = parameterized._pairwise_product_dict
+        testing.product_dict = pairwise_product_dict
+        parameterized.product_dict = pairwise_product_dict
+
+
+def pytest_collection_finish(session):
+    if _pairwise_parameterize == 'always':
+        product_dict = parameterized._product_dict_orig
+        testing.product_dict = product_dict
+        parameterized.product_dict = product_dict