diff --git a/conftest.py b/conftest.py
deleted file mode 100644
index e4e478d2d72d7..0000000000000
--- a/conftest.py
+++ /dev/null
@@ -1,6 +0,0 @@
-# Even if empty this file is useful so that when running from the root folder
-# ./sklearn is added to sys.path by pytest. See
-# https://docs.pytest.org/en/latest/explanation/pythonpath.html for more
-# details. For example, this allows to build extensions in place and run pytest
-# doc/modules/clustering.rst and use sklearn from the local folder rather than
-# the one from site-packages.
diff --git a/sklearn/conftest.py b/sklearn/conftest.py
index d15f9fe2ec142..d2f44f6912b62 100644
--- a/sklearn/conftest.py
+++ b/sklearn/conftest.py
@@ -12,7 +12,7 @@
 from _pytest.doctest import DoctestItem
 from threadpoolctl import threadpool_limits
 
-from sklearn import config_context
+from sklearn import config_context, set_config
 from sklearn._min_dependencies import PYTEST_MIN_VERSION
 from sklearn.datasets import (
     fetch_20newsgroups,
@@ -278,3 +278,11 @@ def mocked_import(name, *args, **kwargs):
         return import_orig(name, *args, **kwargs)
 
     monkeypatch.setattr(builtins, "__import__", mocked_import)
+
+
+@pytest.fixture
+def print_changed_only_false():
+    """Set `print_changed_only` to False for the duration of the test."""
+    set_config(print_changed_only=False)
+    yield
+    set_config(print_changed_only=True)  # reset to default
diff --git a/sklearn/externals/conftest.py b/sklearn/externals/conftest.py
index c617107866b92..7f7a4af349878 100644
--- a/sklearn/externals/conftest.py
+++ b/sklearn/externals/conftest.py
@@ -4,4 +4,3 @@
 # using --pyargs
 def pytest_ignore_collect(path, config):
     return True
-
diff --git a/sklearn/utils/tests/conftest.py b/sklearn/utils/tests/conftest.py
deleted file mode 100644
index 148225a481f69..0000000000000
--- a/sklearn/utils/tests/conftest.py
+++ /dev/null
@@ -1,10 +0,0 @@
-import pytest
-
-import sklearn
-
-
-@pytest.fixture
-def print_changed_only_false():
-    sklearn.set_config(print_changed_only=False)
-    yield
-    sklearn.set_config(print_changed_only=True)  # reset to default