diff --git a/book/source/01-intro.md b/book/source/01-intro.md
index e9d7cbb..b26e7f4 100644
--- a/book/source/01-intro.md
+++ b/book/source/01-intro.md
@@ -19,7 +19,7 @@ Three groups of people interact with OpenPGP:
 2. Software developers who build applications that contain OpenPGP functionality
 3. Implementers of OpenPGP libraries (or other software that directly handles the processing of internal OpenPGP data structures)
 
-This document is focused on the second group, application developers, who use OpenPGP functionality in their software projects. It describes the properties of the OpenPGP system and its uses. It presupposes solid knowledge of software development concepts and of general cryptographic concepts. Thus, this text describes OpenPGP at the "library-level," teaching concepts that will help software developers get started as a user of any implementation (e.g., [OpenPGP.JS](https://openpgpjs.org/), [Sequoia-PGP](https://sequoia-pgp.org/)).
+This document is focused on the second group, application developers, who use OpenPGP functionality in their software projects. It describes the properties of the OpenPGP system and its uses. It presupposes solid knowledge of software development concepts and of general cryptographic concepts. Thus, this text describes OpenPGP at the "library-level," teaching concepts that will help software developers get started as a user of any implementation (e.g., [OpenPGP.js](https://openpgpjs.org/), [Sequoia-PGP](https://sequoia-pgp.org/)).
 
 ```{admonition} TODO
 :class: warning