diff --git a/nixos/doc/manual/development/option-types.section.md b/nixos/doc/manual/development/option-types.section.md
index 44bb3b4782e1..2ad3d6c4f949 100644
--- a/nixos/doc/manual/development/option-types.section.md
+++ b/nixos/doc/manual/development/option-types.section.md
@@ -528,7 +528,7 @@ The only required parameter is `name`.
 
 :   A string representation of the type function name.
 
-`definition`
+`description`
 
 :   Description of the type used in documentation. Give information of
     the type and any of its arguments.