diff --git a/classes/plagiarism_pchkorg_api_provider.php b/classes/plagiarism_pchkorg_api_provider.php
index d5f4984..bb2d328 100644
--- a/classes/plagiarism_pchkorg_api_provider.php
+++ b/classes/plagiarism_pchkorg_api_provider.php
@@ -455,7 +455,7 @@ class plagiarism_pchkorg_api_provider {
      */
     public function user_email_to_hash($email) {
         // We don't send raw user email to the service.
-        return hash('sha256', $this->token . $email);
+        return hash('sha256', $this->token . strtolower($email));
     }
 
     /**
diff --git a/version.php b/version.php
index 7fe352e..ba54e87 100644
--- a/version.php
+++ b/version.php
@@ -26,9 +26,9 @@ defined('MOODLE_INTERNAL') || die();
 if (!isset($plugin)) {
     $plugin = new stdClass();
 }
-$plugin->version = 2022103115;
+$plugin->version = 2022110417;
 $plugin->requires = 2020061501; // Requires Moodle 3.9 .
-$plugin->release = 'v3.12.3';
+$plugin->release = 'v3.12.4';
 $plugin->component = 'plagiarism_pchkorg';
 $plugin->maturity = MATURITY_STABLE;
 $plugin->dependencies = array(