diff --git a/product_price_list.diff b/product_price_list.diff
new file mode 100644
index 0000000..d6a75fa
--- /dev/null
+++ b/product_price_list.diff
@@ -0,0 +1,15 @@
+diff --git a/tryton/trytond/trytond/modules/product_price_list/price_list.py b/trytond/trytond/modules/product_price_list/price_list.py
+index 8d7299ed58..4c68662e1d 100644
+--- a/tryton/trytond/trytond/modules/product_price_list/price_list.py
++++ b/tryton/trytond/trytond/modules/product_price_list/price_list.py
+@@ -85,8 +85,8 @@ class PriceList(DeactivableMixin, ModelSQL, ModelView):
+         return {
+             'names': {
+                 'unit_price': unit_price if unit_price is not None else Null(),
+-                'cost_price': cost_price if unit_price is not None else Null(),
+-                'list_price': list_price if unit_price is not None else Null(),
++                'cost_price': cost_price if cost_price is not None else Null(),
++                'list_price': list_price if list_price is not None else Null(),
+                 },
+             }
+
diff --git a/series b/series
index 7669a03..2ff295b 100644
--- a/series
+++ b/series
@@ -67,3 +67,5 @@ issue12799.diff # [sao] Convert negative id value as None when set by the client
 issue12547.diff # [stock_lot] Check lot required only when changing move to done
 
 issue12823.diff # [account] Use 0 as fallback for missing debit or credit in on_change functions
+
+product_price_list.diff # [product_price_list] Fix cost_price and list_price values