diff --git a/bilby/gw/conversion.py b/bilby/gw/conversion.py
index 9a5e792085b94ff0ed9370cb2c50891d79b6fdfa..6faf0d4552000f124aba3f1ba0e9048f7dfe1e4e 100644
--- a/bilby/gw/conversion.py
+++ b/bilby/gw/conversion.py
@@ -192,7 +192,7 @@ def convert_to_lal_binary_black_hole_parameters(parameters):
 
     converted_parameters = parameters.copy()
     original_keys = list(converted_parameters.keys())
-    if 'luminosity_distance' not in converted_parameters.keys():
+    if 'luminosity_distance' not in original_keys:
         if 'redshift' in converted_parameters.keys():
             converted_parameters['luminosity_distance'] = \
                 redshift_to_luminosity_distance(parameters['redshift'])