diff --git a/rails6/en/chapter07-placing-orders.adoc b/rails6/en/chapter07-placing-orders.adoc
index c4f3384..3358b1e 100644
--- a/rails6/en/chapter07-placing-orders.adoc
+++ b/rails6/en/chapter07-placing-orders.adoc
@@ -504,7 +504,7 @@ We can now add the implementation:
 class Order < ApplicationRecord
   # ...
   def set_total!
-    self.total = products.sum :price
+    self.total = self.products.map(&:price).sum
   end
 end
 ----
diff --git a/rails6/es/chapter07-placing-orders.adoc b/rails6/es/chapter07-placing-orders.adoc
index 50db52f..944ee90 100644
--- a/rails6/es/chapter07-placing-orders.adoc
+++ b/rails6/es/chapter07-placing-orders.adoc
@@ -503,7 +503,7 @@ Ahora podemos añadir la implementación:
 class Order < ApplicationRecord
   # ...
   def set_total!
-    self.total = products.sum :price
+    self.total = self.products.map(&:price).sum
   end
 end
 ----
diff --git a/rails6/fr/chapter07-placing-orders.adoc b/rails6/fr/chapter07-placing-orders.adoc
index f6bfdfe..eb2f623 100644
--- a/rails6/fr/chapter07-placing-orders.adoc
+++ b/rails6/fr/chapter07-placing-orders.adoc
@@ -489,7 +489,7 @@ Nous pouvons maintenant ajouter l'implémentation:
 class Order < ApplicationRecord
   # ...
   def set_total!
-    self.total = self.products.sum :price
+    self.total = self.products.map(&:price).sum
   end
 end
 ----