diff --git a/tutorials/BasicTutorial.py b/tutorials/BasicTutorial.py
index de671e99edaa78f0d3ef7a51dd1ce3e2e4b2cd93..6330399a952e4809e2b6d0e61989a365e4f2eb7f 100644
--- a/tutorials/BasicTutorial.py
+++ b/tutorials/BasicTutorial.py
@@ -71,17 +71,17 @@ IFOs = [H1, L1]
 
 likelihood = peyote.likelihood.Likelihood(IFOs, source)
 
-prior = simulation_parameters.copy()
-prior['mass_1'] = peyote.parameter.Parameter(
+prior = source.copy()
+prior.mass_1 = peyote.parameter.Parameter(
     'mass_1', prior=peyote.prior.Uniform(lower=35, upper=37),
     latex_label='$m_1$')
-prior['mass_2'] = peyote.parameter.Parameter(
+prior.mass_2 = peyote.parameter.Parameter(
     'mass_2', prior=peyote.prior.Uniform(lower=27, upper=31),
     latex_label='$m_2$')
-prior['iota'] = peyote.parameter.Parameter(
+prior.iota = peyote.parameter.Parameter(
     'iota', prior=peyote.prior.Uniform(lower=0, upper=np.pi),
     latex_label='$iota$')
-prior['luminosity_distance'] = peyote.parameter.Parameter(
+prior.luminosity_distance = peyote.parameter.Parameter(
     'luminosity_distance', prior=peyote.prior.Uniform(lower=300, upper=600),
     latex_label='$d_L$')