diff --git a/1.1-Overview.md b/1.1-Overview.md
index ea263e7..906c15e 100644
--- a/1.1-Overview.md
+++ b/1.1-Overview.md
@@ -23,7 +23,7 @@ Here is how it basically works:
   * The contents of `prefs.js` override the default values shown in `about:config`
   * If a preference in `prefs.js` has a data mismatch, then it is ignored and the ~~default~~ **previous value** is retained (this could be the default or a user-set value set earlier within about:config) and shown in `about:config`
 * In `about:config`
-  * All values stored in `prefs.js`, even if they are the default value, will be denoted as status `user set`. In Firefox 56+ it is denoted as `modifed`
+  * All values stored in `prefs.js`, even if they are the default value, will be denoted as status `user set`. In Firefox 55+ it is denoted as `modifed`
   * If you set a value to a `user set`/`modifed` value, it is stored in `prefs.js`
   * If you reset a value to `default`, it is removed from `prefs.js`
   * If you reset a `hidden preference` to default, the value will be blank, and assuming it is not applied again from a `user.js`, it will then vanish on the next about:config reload