diff --git a/README.md b/README.md
index 8e343a4eb7..71eeef5def 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,7 @@
 - ⚡ built for speed
 - ⬇️ low-level compiler for parsing markdown without caching or blocking for long periods of time
 - ⚖️ light-weight while implementing all markdown features from the supported flavors & specifications
+- 🛠️ easily adaptable with [custom extensions](https://marked.js.org/using_advanced#extensions)
 - 🌐 works in a browser, on a server, or from a command line interface (CLI)
 
 ## Demo
diff --git a/docs/INDEX.md b/docs/INDEX.md
index 7254ef45b4..fe9903c518 100644
--- a/docs/INDEX.md
+++ b/docs/INDEX.md
@@ -3,10 +3,11 @@ Marked is
 1. built for speed.<sup>*</sup>
 2. a low-level markdown compiler for parsing markdown without caching or blocking for long periods of time.<sup>**</sup>
 3. light-weight while implementing all markdown features from the supported flavors & specifications.<sup>***</sup>
-4. available as a command line interface (CLI) and running in client- or server-side JavaScript projects.
+4. easily adaptable with [custom extensions](/using_advanced#extensions).
+5. available as a command line interface (CLI) and running in client- or server-side JavaScript projects.
 
 <p><small><sup>*</sup> Still working on metrics for comparative analysis and definition.</small><br>
-<small><sup>**</sup> As few dependencies as possible.</small><br>
+<small><sup>**</sup> Zero dependencies.</small><br>
 <small><sup>***</sup> Strict compliance could result in slower processing when running comparative benchmarking.</small></p>