diff --git a/csaf_2.1/prose/edit/src/additional-conventions.md b/csaf_2.1/prose/edit/src/additional-conventions.md
index 9e59a5774..70293e2f1 100644
--- a/csaf_2.1/prose/edit/src/additional-conventions.md
+++ b/csaf_2.1/prose/edit/src/additional-conventions.md
@@ -81,7 +81,7 @@ The `/product_tree` uses a nested structure for `branches`. Along a single path
 
 ## Hardware and Software within the Product Tree
 
-If a product consists of hardware and software, the hardware part MUST be presented as one product in the product tree and the software part as another on.
+If a product consists of hardware and software, the hardware part MUST be presented as one product in the product tree and the software part as another one.
 To form the overall product, both parts MUST be combined through a relationship.
 
 *Examples 1:*