diff --git a/snudda/neurons/neuron_model_extended.py b/snudda/neurons/neuron_model_extended.py
index 198633b0d..721be3aed 100644
--- a/snudda/neurons/neuron_model_extended.py
+++ b/snudda/neurons/neuron_model_extended.py
@@ -243,11 +243,14 @@ def define_parameters(self, parameter_config, parameter_id=None, parameter_key=N
                         bounds=bounds,
                         value=value))
             elif param_config['type'] in ['section', 'range']:
+             
                 if param_config['dist_type'] == 'uniform':
                     scaler = ephys.parameterscalers.NrnSegmentLinearScaler()
                 elif param_config['dist_type'] in ['exp', 'distance']:
                     scaler = ephys.parameterscalers.NrnSegmentSomaDistanceScaler(distribution=param_config['dist'])
-
+                else:
+                    raise ValueError(f"Unknown dist_type = {param_config['dist_type']}, "
+                                     f"expected 'uniform', 'exp' or 'distance'")
                 # 2024-07-23: Updated format, so that "sectionlist" is allowed to be either a string (of one section type)
                 #             or a list of strings with section types.