diff --git a/API/Schema/Chapter.cs b/API/Schema/Chapter.cs
index 65e5811..56233be 100644
--- a/API/Schema/Chapter.cs
+++ b/API/Schema/Chapter.cs
@@ -21,8 +21,8 @@ public class Chapter : IComparable<Chapter>
     public string ParentMangaId { get; internal set; }
     public Manga? ParentManga { get; init; }
 
-    public Chapter(Manga parentManga, string url, string chapterNumberStruct, int? volumeNumber = null, string? title = null)
-        : this(parentManga.MangaId, url, chapterNumberStruct, volumeNumber, title)
+    public Chapter(Manga parentManga, string url, string chapterNumber, int? volumeNumber = null, string? title = null)
+        : this(parentManga.MangaId, url, chapterNumber, volumeNumber, title)
     {
         this.ParentManga = parentManga;
         this.ArchiveFileName = BuildArchiveFileName();
diff --git a/API/Tranga.cs b/API/Tranga.cs
index e6d89a3..775e311 100644
--- a/API/Tranga.cs
+++ b/API/Tranga.cs
@@ -1,6 +1,5 @@
 using API.Schema;
 using API.Schema.Jobs;
-using API.Schema.NotificationConnectors;
 using log4net;
 using log4net.Config;
 
@@ -8,10 +7,10 @@ namespace API;
 
 public static class Tranga
 {
-    public static Thread NotificationSenderThread { get; } = new (NotificationSender);
-    public static Thread JobStarterThread { get; } = new (JobStarter);
     private static readonly Dictionary<Thread, Job> RunningJobs = new();
     private static readonly ILog Log = LogManager.GetLogger(typeof(Tranga));
+    public static Thread NotificationSenderThread { get; } = new(NotificationSender);
+    public static Thread JobStarterThread { get; } = new(JobStarter);
 
     internal static void StartLogger()
     {
@@ -20,10 +19,11 @@ public static class Tranga
 
     private static void NotificationSender(object? pgsqlContext)
     {
-        if(pgsqlContext is null) return;
-        PgsqlContext context = (PgsqlContext)pgsqlContext;
+        if (pgsqlContext is null) return;
+        var context = (PgsqlContext)pgsqlContext;
 
-        IQueryable<Notification> staleNotifications = context.Notifications.Where(n => n.Urgency < NotificationUrgency.Normal);
+        var staleNotifications =
+            context.Notifications.Where(n => n.Urgency < NotificationUrgency.Normal);
         context.Notifications.RemoveRange(staleNotifications);
         context.SaveChanges();
         while (true)
@@ -31,7 +31,7 @@ public static class Tranga
             SendNotifications(context, NotificationUrgency.High);
             SendNotifications(context, NotificationUrgency.Normal);
             SendNotifications(context, NotificationUrgency.Low);
-            
+
             context.SaveChanges();
             Thread.Sleep(2000);
         }
@@ -39,47 +39,53 @@ public static class Tranga
 
     private static void SendNotifications(PgsqlContext context, NotificationUrgency urgency)
     {
-        List<Notification> notifications = context.Notifications.Where(n => n.Urgency == urgency).ToList();
+        var notifications = context.Notifications.Where(n => n.Urgency == urgency).ToList();
         if (notifications.Any())
         {
-            DateTime max = notifications.MaxBy(n => n.Date)!.Date;
+            var max = notifications.MaxBy(n => n.Date)!.Date;
             if (DateTime.Now.Subtract(max) > TrangaSettings.NotificationUrgencyDelay(urgency))
             {
-                foreach (NotificationConnector notificationConnector in context.NotificationConnectors)
-                {
-                    foreach (Notification notification in notifications)
-                        notificationConnector.SendNotification(notification.Title, notification.Message);
-                }
+                foreach (var notificationConnector in context.NotificationConnectors)
+                foreach (var notification in notifications)
+                    notificationConnector.SendNotification(notification.Title, notification.Message);
                 context.Notifications.RemoveRange(notifications);
             }
         }
+
         context.SaveChanges();
     }
 
     private static void JobStarter(object? pgsqlContext)
     {
-        if(pgsqlContext is null) return;
-        PgsqlContext context = (PgsqlContext)pgsqlContext;
-        
-        string TRANGA = "\n\n _______                                   \n|_     _|.----..---.-..-----..-----..---.-.\n  |   |  |   _||  _  ||     ||  _  ||  _  |\n  |___|  |__|  |___._||__|__||___  ||___._|\n                             |_____|       \n\n";
+        if (pgsqlContext is null) return;
+        var context = (PgsqlContext)pgsqlContext;
+
+        var TRANGA =
+            "\n\n _______                                   \n|_     _|.----..---.-..-----..-----..---.-.\n  |   |  |   _||  _  ||     ||  _  ||  _  |\n  |___|  |__|  |___._||__|__||___  ||___._|\n                             |_____|       \n\n";
         Log.Info(TRANGA);
         while (true)
         {
-            List<Job> completedJobs = context.Jobs.Where(j => j.state == JobState.Completed).ToList();
-            foreach (Job job in completedJobs)
-                if(job.RecurrenceMs <= 0)
+            var completedJobs = context.Jobs.Where(j => j.state == JobState.Completed).ToList();
+            foreach (var job in completedJobs)
+                if (job.RecurrenceMs <= 0)
+                {
                     context.Jobs.Remove(job);
+                }
                 else
                 {
                     job.LastExecution = DateTime.UtcNow;
                     job.state = JobState.Waiting;
                     context.Jobs.Update(job);
                 }
-            
-            List<Job> runJobs = context.Jobs.Where(j => j.state <= JobState.Running).ToList().Where(j => j.NextExecution < DateTime.UtcNow).ToList();
-            foreach (Job job in runJobs)
+
+            List<Job> runJobs = context.Jobs.Where(j => j.state <= JobState.Running).AsEnumerable()
+                .Where(j => j.NextExecution < DateTime.UtcNow).ToList();
+            foreach (var job in runJobs)
             {
-                Thread t = new (() =>
+                // If the job is already running, skip it
+                if (RunningJobs.Values.Any(j => j.JobId == job.JobId)) continue;
+
+                Thread t = new(() =>
                 {
                     IEnumerable<Job> newJobs = job.Run(context);
                     context.Jobs.AddRange(newJobs);
@@ -96,7 +102,7 @@ public static class Tranga
                 RunningJobs.Remove(thread.thread);
                 context.Jobs.Update(thread.job);
             }
-            
+
             context.SaveChanges();
             Thread.Sleep(2000);
         }