diff --git a/oslo_config/sphinxconfiggen.py b/oslo_config/sphinxconfiggen.py
index ff7172cb..616e8573 100644
--- a/oslo_config/sphinxconfiggen.py
+++ b/oslo_config/sphinxconfiggen.py
@@ -91,3 +91,7 @@ def setup(app):
     app.add_config_value('config_generator_config_file', None, 'env')
     app.add_config_value('sample_config_basename', None, 'env')
     app.connect('builder-inited', generate_sample)
+    return {
+        'parallel_read_safe': True,
+        'parallel_write_safe': True,
+    }
diff --git a/oslo_config/sphinxext.py b/oslo_config/sphinxext.py
index 905490c7..4a111633 100644
--- a/oslo_config/sphinxext.py
+++ b/oslo_config/sphinxext.py
@@ -508,3 +508,7 @@ def setup(app):
     oslo_i18n.enable_lazy(False)
     app.add_directive('show-options', ShowOptionsDirective)
     app.add_domain(ConfigDomain)
+    return {
+        'parallel_read_safe': True,
+        'parallel_write_safe': True,
+    }