diff --git a/blueice/likelihood.py b/blueice/likelihood.py
index f3fdaba..ba8eb76 100644
--- a/blueice/likelihood.py
+++ b/blueice/likelihood.py
@@ -115,10 +115,8 @@ def source_shape_parameters(self):
         """Dict of sources with shape parameters. source name -> dict of shape parameters."""
         source_shape_parameters = OrderedDict()
         for sn, source in zip(self.source_name_list, self.base_model.sources):
-            parameter_names = source.parameters
-            if parameter_names is None:
-                raise ValueError("The `parameters` of each source need to be specified when using `source_wise_interpolation`.")
-            shape_parameters = OrderedDict({k: v for k, v in self.shape_parameters.items() if k in parameter_names})
+            dont_hash_settings = source.config['dont_hash_settings']
+            shape_parameters = OrderedDict({k: v for k, v in self.shape_parameters.items() if k not in dont_hash_settings})
             if shape_parameters:
                 source_shape_parameters[sn] = shape_parameters
         return source_shape_parameters
diff --git a/blueice/source.py b/blueice/source.py
index 9bcbeb9..145a260 100644
--- a/blueice/source.py
+++ b/blueice/source.py
@@ -86,8 +86,6 @@ def __init__(self, config, *args, **kwargs):
         self.name = c['name']
         del c['name']
 
-        self.parameters = c.pop('parameters', None)
-
         # events_per_day and fraction_in_range may be modified / set properly for the first time later (see comments
         # in 'defaults' above)
         if hasattr(self, 'events_per_day'):
diff --git a/tests/test_likelihood.py b/tests/test_likelihood.py
index 20dbf9b..d67d79c 100644
--- a/tests/test_likelihood.py
+++ b/tests/test_likelihood.py
@@ -106,8 +106,6 @@ def test_source_wise_interpolation():
     ret_1 = lf(full_output=True, mu=1)
 
     config["source_wise_interpolation"] = True
-    # We need to specify all parameters used by each source
-    config["sources"][0]["parameters"] = ["mu", "sigma", "strlen_multiplier", "some_multiplier", "s0_rate_multiplier"]
     lf_source_wise = UnbinnedLogLikelihood(config)
     lf_source_wise.add_shape_parameter("mu", anchors={-2:-2, 0:0, 2:2})
     lf_source_wise.prepare()