diff --git a/lib/ansible/modules/system/vdo.py b/lib/ansible/modules/system/vdo.py
index 3cc3d37938..716893de8f 100644
--- a/lib/ansible/modules/system/vdo.py
+++ b/lib/ansible/modules/system/vdo.py
@@ -570,6 +570,7 @@ def run_module():
         # The 'vdo status' keys that are currently modifiable.
         statusparamkeys = ['Acknowledgement threads',
                            'Bio submission threads',
+                           'Block map cache size',
                            'CPU-work threads',
                            'Logical threads',
                            'Physical threads',