diff --git a/lib/ansible/modules/cloud/amazon/elasticache.py b/lib/ansible/modules/cloud/amazon/elasticache.py
index 5a9c11fdeb5..47a6b568853 100644
--- a/lib/ansible/modules/cloud/amazon/elasticache.py
+++ b/lib/ansible/modules/cloud/amazon/elasticache.py
@@ -42,6 +42,7 @@ options:
     description:
       - The version number of the cache engine
     required: false
+    default: none
   node_type:
     description:
       - The compute and memory capacity of the nodes in the cache cluster