diff --git a/src/Notebook_Processor/configuration/models/configuration_model.py b/src/Notebook_Processor/configuration/models/configuration_model.py
index de35bd72a7785f8820d76038138893d044449c60..7f24827b4fdc0f9332735d9c2bc5d57f885af26a 100644
--- a/src/Notebook_Processor/configuration/models/configuration_model.py
+++ b/src/Notebook_Processor/configuration/models/configuration_model.py
@@ -29,7 +29,9 @@ class ConfigurationModel(ConfiguredBaseModel):
         Causes defaults to get validated as a side effect.
         Since this only happens during the startup of the application, I consider this to be a positive side effect that protects against errors.
         """
-        assert isinstance(data, dict)
+        if not isinstance(data, dict):
+            raise TypeError(f"data must be a dict, not {type(data)}")
+
         for field, info in cls.model_fields.items():
             data.setdefault(field, environ.get(field, info.default))
         return data