diff --git a/modules/sale/sale_reporting.py b/modules/sale/sale_reporting.py
index ebe2daae35..d308305a3e 100644
--- a/modules/sale/sale_reporting.py
+++ b/modules/sale/sale_reporting.py
@@ -403,7 +403,7 @@ class CustomerCategoryMixin:
         # by using a number one order bigger.
         nb_category = category.select(
             Power(10, (Ceil(Log(Max(category.id))) + Literal(1))))
-        return Min(line.id * nb_category + party_category.id)
+        return cls.id.sql_cast(Min(line.id * nb_category + party_category.id))
 
     @classmethod
     def _group_by(cls, tables, withs):
@@ -643,7 +643,8 @@ class ProductCategoryMixin(object):
         # by using number one order bigger.
         nb_category = category.select(
             Power(10, (Ceil(Log(Max(category.id))) + Literal(1))))
-        return Min(line.id * nb_category + template_category.id)
+        return cls.id.sql_cast(
+            Min(line.id * nb_category + template_category.id))
 
     @classmethod
     def _group_by(cls, tables, withs):
diff --git a/modules/stock/stock_reporting_margin.py b/modules/stock/stock_reporting_margin.py
index 60eb6fc564..622bec83b8 100644
--- a/modules/stock/stock_reporting_margin.py
+++ b/modules/stock/stock_reporting_margin.py
@@ -468,7 +468,8 @@ class CategoryMixin:
         # by using number one order bigger.
         nb_category = category.select(
             Power(10, (Ceil(Log(Max(category.id))) + Literal(1))))
-        return Min(move.id * nb_category + template_category.id)
+        return cls.id.sql_cast(
+            Min(move.id * nb_category + template_category.id))
 
     @classmethod
     def _group_by(cls, tables, withs):