diff --git a/source/app/models/main.py b/source/app/models/main.py
index 71e92e4..305c03c 100644
--- a/source/app/models/main.py
+++ b/source/app/models/main.py
@@ -2219,7 +2219,10 @@ class Productos(BaseModel):
                 .order_by(Productos.clave)
                 .tuples()
             )
-            value = max([int(v[0]) for v in values if v[0].isdigit()])
+            values = [int(v[0]) for v in values if v[0].isdigit()]
+            value = 0
+            if values:
+                value = max(values)
 
         value = value or 0
         value += 1