diff --git a/lib/ansible/utils/module_docs.py b/lib/ansible/utils/module_docs.py
index 1565bb3be87..9a7ee0ae33b 100644
--- a/lib/ansible/utils/module_docs.py
+++ b/lib/ansible/utils/module_docs.py
@@ -23,6 +23,7 @@ import ast
 import yaml
 import traceback
 
+from collections import MutableMapping
 from ansible.plugins import fragment_loader
 
 # modules that are ok that they do not have documentation strings