diff --git a/classes/notification.php b/classes/notification.php
index 762bbd7..d39dd88 100644
--- a/classes/notification.php
+++ b/classes/notification.php
@@ -60,6 +60,11 @@ class Notification
         $sql = "SELECT DISTINCT subscriberIDFK FROM services_subscriber WHERE serviceIDFK IN (" . $this->serviceids . ")";
         $query = $mysqli->query($sql);
 
+        if (0 === $query->num_rows) {
+          // skip processing if no one needs to be notified
+          return;
+        }
+
         // Create the queue tasks for email/telegram notifications
         $queue = new Queue();
         $queue->status  = $queue->all_status['populating'];
diff --git a/classes/queue.php b/classes/queue.php
index dd8187c..a1836b3 100644
--- a/classes/queue.php
+++ b/classes/queue.php
@@ -114,7 +114,7 @@ class Queue
     }
 
     // TODO: Fix max attempts for notifications
-    public function process_queue(){
+    public static function process_queue(){
       global $mysqli;
       $stmt = $mysqli->query("SELECT qn.id, qn.task_id, qn.status, qn.subscriber_id, qn.retries, sub.firstname, sub.userID, sub.token FROM queue_notify AS qn INNER JOIN subscribers AS sub ON qn.subscriber_id = sub.subscriberID WHERE qn.status NOT LIKE 2 AND sub.active=1");
       while ( $result = $stmt->fetch_assoc() ) {
diff --git a/classes/service-group.php b/classes/service-group.php
index 933571a..f94fc72 100644
--- a/classes/service-group.php
+++ b/classes/service-group.php
@@ -153,7 +153,7 @@ class ServiceGroup
    * Get list of services groups.
    * @return array $groups
    */
-  public function get_groups() {
+  public static function get_groups() {
     global $mysqli;
     $stmt = $mysqli->query("SELECT id, name FROM services_groups ORDER by name ASC");