diff --git a/Tools/autotest/param_metadata/param.py b/Tools/autotest/param_metadata/param.py
index 0b80bc7442..6497ee164e 100644
--- a/Tools/autotest/param_metadata/param.py
+++ b/Tools/autotest/param_metadata/param.py
@@ -100,6 +100,7 @@ known_units = {
              'A/V'     : 'ampere per volt'       ,
              'm/V'     : 'meters per volt'       ,
              'gravities': 'standard acceleration due to gravity' , # g_n would be a more correct unit, but IMHO no one understands what g_n means
+             'octal'   : 'octal'                 ,
              }
 
 required_param_fields = [