diff --git a/openfisca_web_api/controllers.py b/openfisca_web_api/controllers.py
index <HASH>..<HASH> 100644
--- a/openfisca_web_api/controllers.py
+++ b/openfisca_web_api/controllers.py
@@ -397,6 +397,7 @@ def api1_field(req):
             headers = headers,
             )
 
+    model.tax_benefit_system.set_variables_dependencies()
     simulation = simulations.Simulation(
         period = periods.period(datetime.date.today().year),
         tax_benefit_system = model.tax_benefit_system,
Compute consumers of variable before returning a field JSON.