diff --git a/examples/gw_examples/injection_examples/binary_neutron_star_example.py b/examples/gw_examples/injection_examples/binary_neutron_star_example.py
index 68aa76d10ab989bec1e00857924c68df9b19b2bc..bbcce5925d88b7cfc6e227804ee3dd9327e666fc 100644
--- a/examples/gw_examples/injection_examples/binary_neutron_star_example.py
+++ b/examples/gw_examples/injection_examples/binary_neutron_star_example.py
@@ -70,8 +70,7 @@ priors = bilby.gw.prior.BNSPriorDict()
 for key in ['psi', 'geocent_time', 'ra', 'dec', 'chi_1', 'chi_2',
             'theta_jn', 'luminosity_distance', 'phase']:
     priors[key] = injection_parameters[key]
-priors.pop('mass_1')
-priors.pop('mass_2')
+priors.pop('mass_ratio')
 priors.pop('lambda_1')
 priors.pop('lambda_2')
 priors['chirp_mass'] = bilby.core.prior.Gaussian(