diff --git a/wizard/wizard_siren.py b/wizard/wizard_siren.py
index 20ec2ab36888db461e1273b28004baecfa95c592..e566376af2bc818dbb5402a2e5293ecfa8ac8b84 100644
--- a/wizard/wizard_siren.py
+++ b/wizard/wizard_siren.py
@@ -66,6 +66,7 @@ class SirenWizard(models.TransientModel):
 				new_company.lib_ape = company['fields']['libapet']
 			if company['fields'].get('dateess'):
 				new_company.date_ess = company['fields']['dateess']
+			if company['fields'].get('ess') == "O":
 				new_company.ess = True
 			if company['fields'].get('libessen'):
 				new_company.lib_ess = company['fields']['libessen']