diff --git a/openfisca_web_api/handlers.py b/openfisca_web_api/handlers.py
index 4c8c4585f..b903a358d 100644
--- a/openfisca_web_api/handlers.py
+++ b/openfisca_web_api/handlers.py
@@ -75,7 +75,7 @@ def calculate(self, tax_benefit_system, input_data: dict) -> dict:
 
         return input_data
 
-    def trace(self, tax_benefit_system, input_data, simulation_configurator=None):
+    def trace(self, tax_benefit_system, input_data):
         simulation = SimulationBuilder().build_from_entities(tax_benefit_system, input_data)
         self.simulation_configurator(simulation)
         simulation.trace = True