diff --git a/product/ERP5/Document/InvoiceCell.py b/product/ERP5/Document/InvoiceCell.py
index d908ed1e16a2c424c4e05abe3d19f561fc99a8ef..f3a1dbfd1d520b8a6e500c6e02657c260846dd60 100755
--- a/product/ERP5/Document/InvoiceCell.py
+++ b/product/ERP5/Document/InvoiceCell.py
@@ -154,4 +154,4 @@ Une ligne tarifaire."""
       """
         Return the criterion for grouping. This should be overriden by each class.
       """
-      return self.getPrice()
+      return int(round(self.getPrice() * 100))
diff --git a/product/ERP5/Document/InvoiceLine.py b/product/ERP5/Document/InvoiceLine.py
index 5cd10d2d094856e8ae5e74b15bfe6e412c86f9bb..f397921fbd5b595805b30fe7fe0a8e17cd243ab8 100755
--- a/product/ERP5/Document/InvoiceLine.py
+++ b/product/ERP5/Document/InvoiceLine.py
@@ -164,4 +164,4 @@ Une ligne tarifaire."""
       """
         Return the criterion for grouping. This should be overriden by each class.
       """
-      return self.getPrice()
+      return int(round(self.getPrice() * 100))