diff --git a/CHANGES.md b/CHANGES.md
index 7159f587..56c4cead 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,5 +1,15 @@
 # Changelog
 
+### 6.4.0 (2026-10-08)
+
+- new feature: allow hiding correct answer from feedback
+- improvement: for Adaptive Mode, only show part's general feedback when finished
+- improvement: make sure sigfig() follows PHP convention for scientific notation
+- bugfix: remove empty strings from language file
+- bugfix: fix Adaptive Mode not working in "no penalty" variant
+- internal: update CI
+- internal: assure full compatibility with Moodle 5.2
+
 ### 6.3.2 (2026-07-03)
 
 - bugfix: keep feedback visible after manual regrading / commenting of question
diff --git a/README.md b/README.md
index 895cee4e..d94c92d1 100644
--- a/README.md
+++ b/README.md
@@ -19,9 +19,9 @@ Jean-Michel Védrine.
 
 This version is compatible with Moodle 4.5 and newer. It has been tested with:
 - Moodle 4.5 using PHP 8.1, PHP 8.2 and PHP 8.3
-- Moodle 5.0 using PHP 8.2, PHP 8.3 and PHP 8.4
 - Moodle 5.1 using PHP 8.2, PHP 8.3 and PHP 8.4
 - Moodle 5.2 using PHP 8.3 and PHP 8.4
+- Moodle 5.3 using PHP 8.3 and PHP 8.4
 
 
 ### Requirements
diff --git a/version.php b/version.php
index 48560ade..90462953 100644
--- a/version.php
+++ b/version.php
@@ -25,7 +25,7 @@
 defined('MOODLE_INTERNAL') || die();
 
 $plugin->component = 'qtype_formulas';
-$plugin->version = 2026073100;
+$plugin->version = 2026100800;
 
 $plugin->cron = 0;
 $plugin->requires = 2024100700;
@@ -35,7 +35,7 @@
     'qtype_multichoice' => 2015111600,
     'filter_mathjaxloader' => 2024100700,
 ];
-$plugin->supported = [405, 502];
-$plugin->release = '6.3.2';
+$plugin->supported = [405, 503];
+$plugin->release = '6.4.0';
 
 $plugin->maturity = MATURITY_STABLE;