diff --git a/wit/configuration.py b/wit/configuration.py
index be0c71e..1d45674 100644
--- a/wit/configuration.py
+++ b/wit/configuration.py
@@ -74,15 +74,15 @@ class TrainConfig:
 
 def class_to_dict(obj):
     if isinstance(obj, (int, float, str, bool, type(None))):
-        return obj
+        return str(obj)
     elif isinstance(obj, dict):
         return {k: class_to_dict(v) for k, v in obj.items()}
     elif isinstance(obj, list):
-        return {str(index): value for index, value in enumerate(obj)}
+        return {str(index): str(value) for index, value in enumerate(obj)}
     elif hasattr(obj, "__dict__"):
         return {k: class_to_dict(v) for k, v in obj.__dict__.items()}
     else:
-        return obj
+        return str(obj)
 
 
 # train_config = TrainConfig()