diff --git a/enrol/fee/classes/plugin.php b/enrol/fee/classes/plugin.php
index 78cbbcd454621..549247cd7a0ae 100644
--- a/enrol/fee/classes/plugin.php
+++ b/enrol/fee/classes/plugin.php
@@ -45,6 +45,10 @@ public function get_possible_currencies(): array {
             $currencies[$c] = new lang_string($c, 'core_currencies');
         }
 
+        uasort($currencies, function($a, $b) {
+            return strcmp($a, $b);
+        });
+
         return $currencies;
     }
 
diff --git a/payment/classes/helper.php b/payment/classes/helper.php
index f0792b1c932a1..b5dc3c17471d0 100644
--- a/payment/classes/helper.php
+++ b/payment/classes/helper.php
@@ -49,7 +49,7 @@ public static function get_supported_currencies(): array {
             /** @var \paygw_paypal\gateway $classname */
             $classname = '\paygw_' . $plugin . '\gateway';
 
-            $currencies += component_class_callback($classname, 'get_supported_currencies', [], []);
+            $currencies = array_merge($currencies, component_class_callback($classname, 'get_supported_currencies', [], []));
         }
 
         $currencies = array_unique($currencies);