diff --git a/source/app/models/main.py b/source/app/models/main.py
index d83b2cd..906b04f 100644
--- a/source/app/models/main.py
+++ b/source/app/models/main.py
@@ -6034,7 +6034,7 @@ class CfdiNomina(BaseModel):
     def _validate_rules_nomina(self, data):
         receptor = data['receptor']
         if receptor['TipoContrato'] == '99':
-            del data['emisor']['RegistroPatronal']
+            data['emisor'].pop('RegistroPatronal', None)
 
         # ~ NOM 154
         if data['nomina']['TipoNomina'] == 'E':