diff --git a/mira/metamodel/templates.py b/mira/metamodel/templates.py
index 348dedb25..cb389046b 100644
--- a/mira/metamodel/templates.py
+++ b/mira/metamodel/templates.py
@@ -269,7 +269,9 @@ def refinement_of(
     @classmethod
     def from_json(cls, data) -> "Concept":
         # Handle Units
-        if data.get('units'):
+        if isinstance(data, Concept):
+            return data
+        elif data.get('units'):
             data['units'] = Unit.from_json(data['units'])
 
         return cls(**data)