diff --git a/application/config/config.php b/application/config/config.php
index 9d608974..e1d942ba 100644
--- a/application/config/config.php
+++ b/application/config/config.php
@@ -128,16 +128,6 @@ $languages = [
 
 $config['language_codes'] = $languages;
 
-$language_code = isset($_SERVER['HTTP_ACCEPT_LANGUAGE']) ? substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2) : 'en';
-
-$config['language'] =
-    $_GET['language'] ??
-    (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'], $languages[$language_code])
-        ? $languages[$language_code]
-        : Config::LANGUAGE);
-
-$config['language_code'] = array_search($config['language'], $languages) ?: 'en';
-
 /*
 |--------------------------------------------------------------------------
 | Available Languages
diff --git a/application/core/EA_Controller.php b/application/core/EA_Controller.php
index 101bcc61..3c3ae4d7 100644
--- a/application/core/EA_Controller.php
+++ b/application/core/EA_Controller.php
@@ -112,17 +112,50 @@ class EA_Controller extends CI_Controller
      */
     private function configure_language()
     {
-        $session_language = session('language');
-
-        if ($session_language) {
-            $language_codes = config('language_codes');
-
-            config([
-                'language' => $session_language,
-                'language_code' => array_search($session_language, $language_codes) ?: 'en',
-            ]);
+        $language_codes = config('language_codes');
+        // set the language code from the language GET parameter if it's a supported language
+        if (!empty($_GET['language'])) {
+            $queryLanguage = strtolower($_GET['language']);
+            $language_code = array_search($queryLanguage, $language_codes);
+            if (!$language_code) {
+                // check if the ISO 639-1 language code was set as the get parameter
+                $queryLangCode = substr($queryLanguage, 0, 2);
+                if (isset($language_codes[$queryLangCode])) {
+                    $language_code = $queryLangCode;
+                }
+            }
         }
 
+        if (empty($language_code)) {
+            // set the language code from the language SESSION parameter if it's a supported language
+            if (session('language')) {
+                $language_code = array_search(session('language'), $language_codes);
+            }
+            // set the language code from the language header if it's a supported language
+            elseif (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
+                $headerLangCode = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2);
+                if (isset($language_codes[$headerLangCode])) {
+                    $language_code = $headerLangCode;
+                }
+            }
+        }
+
+        // no language set. set it to the default language defined in the config
+        if (!$language_code) {
+            $language = strtolower(Config::LANGUAGE);
+            $language_code = array_search($language, $language_codes);
+        }
+        else {
+            $language = $language_codes[$language_code];
+        }
+
+        session(['language' => $language]);
+
+        config([
+            'language' => $language,
+            'language_code' => $language_code,
+        ]);
+
         $this->lang->load('translations');
     }