diff --git a/tupak/sampler.py b/tupak/sampler.py
index 281da7b52a1493f73a6af30a6aa7bc180434f5c6..970aa150fb6b03fb67fe78091b7154afe613c108 100644
--- a/tupak/sampler.py
+++ b/tupak/sampler.py
@@ -79,6 +79,15 @@ class Sampler(object):
         else:
             raise TypeError('result must either be a Result or None')
 
+    @property
+    def search_parameter_keys(self):
+        return self.__search_parameter_keys
+
+    @property
+    def fixed_parameter_keys(self):
+        return self.__fixed_parameter_keys
+
+
     @property
     def external_sampler(self):
         return self.__external_sampler