diff --git a/.github/workflows/cypress.yml b/.github/workflows/cypress.yml
index b5d02b0..0adb436 100644
--- a/.github/workflows/cypress.yml
+++ b/.github/workflows/cypress.yml
@@ -44,7 +44,7 @@ jobs:
       matrix:
         core:
           - {name: 'WP latest', version: 'latest'}
-          - {name: 'WP minimum', version: 'WordPress/WordPress#6.3'}
+          - {name: 'WP minimum', version: 'WordPress/WordPress#6.4'}
           - {name: 'WP trunk', version: 'WordPress/WordPress#master'}
     steps:
     - name: Checkout
diff --git a/README.md b/README.md
index 8e793c2..5b63fb1 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ Compatible with both the block and classic editors.
 ## Requirements
 
 * PHP 7.4+.
-* WordPress 5.8+.
+* WordPress 6.4+.
 * A secure / SSL (HTTPS) website, front and back end.
 
 ## Installation
diff --git a/insecure-content-warning.php b/insecure-content-warning.php
index 4a22800..e090983 100644
--- a/insecure-content-warning.php
+++ b/insecure-content-warning.php
@@ -4,7 +4,7 @@
  * Plugin URI:        https://wordpress.org/plugins/insecure-content-warning/
  * Description:       Prevent editors from adding insecure content in the editor.
  * Version:           1.2.0
- * Requires at least: 6.3
+ * Requires at least: 6.4
  * Requires PHP:      7.4
  * Author:            10up
  * Author URI:        https://10up.com/
diff --git a/readme.txt b/readme.txt
index c3bf626..f2472d7 100644
--- a/readme.txt
+++ b/readme.txt
@@ -1,7 +1,7 @@
 === Insecure Content Warning ===
 Contributors:      10up, psorensen, adamsilverstein, tlovett, davidrgreen, dkotter, jeffpaul
 Tags:              publishing, publishers, secure content, https, ssl
-Tested up to:      6.5
+Tested up to:      6.6
 Stable tag:        1.2.0
 License:           GPLv2 or later
 License URI:       http://www.gnu.org/licenses/gpl-2.0.html