diff --git a/doc/src/usage.md b/doc/src/usage.md
index 108bbc7f..2c8a7ce2 100644
--- a/doc/src/usage.md
+++ b/doc/src/usage.md
@@ -43,6 +43,7 @@ attribute. We're going to import `typhon` as a flake input and use the
       owner = "$user";
       repo = "$project";
       secrets = ./secrets.age;
+      typhon_url = "$typhon_url";
     };
   };
 }