diff --git a/tests/conftest.py b/tests/conftest.py
index ddb03c7eb..fc16043b6 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -7,6 +7,7 @@
 """
 
 import os
+import shutil
 
 import docutils
 import pytest
@@ -37,3 +38,18 @@ def pytest_report_header(config):
 
 def pytest_assertrepr_compare(op, left, right):
     comparer.pytest_assertrepr_compare(op, left, right)
+
+
+def _initialize_test_directory(session):
+    if 'SPHINX_TEST_TEMPDIR' in os.environ:
+        tempdir = os.path.abspath(os.getenv('SPHINX_TEST_TEMPDIR'))
+        print('Temporary files will be placed in %s.' % tempdir)
+
+        if os.path.exists(tempdir):
+            shutil.rmtree(tempdir)
+
+        os.makedirs(tempdir)
+
+
+def pytest_sessionstart(session):
+    _initialize_test_directory(session)