diff --git a/main/src/main/java/me/blackvein/quests/Quest.java b/main/src/main/java/me/blackvein/quests/Quest.java
index af970741b..edf50ed10 100644
--- a/main/src/main/java/me/blackvein/quests/Quest.java
+++ b/main/src/main/java/me/blackvein/quests/Quest.java
@@ -53,7 +53,7 @@ import me.blackvein.quests.util.Lang;
 import me.clip.placeholderapi.PlaceholderAPI;
 import net.citizensnpcs.api.npc.NPC;
 
-public class Quest {
+public class Quest implements Comparable<Quest> {
 
     protected Quests plugin;
     protected String id;
@@ -70,6 +70,11 @@ public class Quest {
     private final Planner pln = new Planner();
     private final Rewards rews = new Rewards();
     private final Options opts = new Options();
+
+    @Override
+    public int compareTo(final Quest quest) {
+        return id.compareTo(quest.getId());
+    }
     
     public String getId() {
         return id;
diff --git a/main/src/main/java/me/blackvein/quests/Quester.java b/main/src/main/java/me/blackvein/quests/Quester.java
index 20f9ad667..4bec79412 100644
--- a/main/src/main/java/me/blackvein/quests/Quester.java
+++ b/main/src/main/java/me/blackvein/quests/Quester.java
@@ -23,6 +23,7 @@ import java.util.Map.Entry;
 import java.util.Random;
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentSkipListSet;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
@@ -108,7 +109,7 @@ public class Quester implements Comparable<Quester> {
             updateJournal();
         }
     };
-    protected LinkedList<Quest> completedQuests = new LinkedList<Quest>() {
+    protected ConcurrentSkipListSet<Quest> completedQuests = new ConcurrentSkipListSet<Quest>() {
 
         private static final long serialVersionUID = -269110128568487000L;
 
@@ -119,12 +120,12 @@ public class Quester implements Comparable<Quester> {
             return b;
         }
 
-        @Override
+        /*@Override
         public void add(final int index, final Quest element) {
             super.add(index, element);
             updateJournal();
-        }
-
+        }*/
+        
         @Override
         public boolean addAll(final Collection<? extends Quest> c) {
             final boolean b = super.addAll(c);
@@ -132,12 +133,12 @@ public class Quester implements Comparable<Quester> {
             return b;
         }
 
-        @Override
+        /*@Override
         public boolean addAll(final int index, final Collection<? extends Quest> c) {
             final boolean b = super.addAll(index, c);
             updateJournal();
             return b;
-        }
+        }*/
 
         @Override
         public void clear() {
@@ -151,8 +152,15 @@ public class Quester implements Comparable<Quester> {
             updateJournal();
             return b;
         }
-
+        
         @Override
+        public boolean removeAll(final Collection<?> c) {
+            final boolean b = super.removeAll(c);
+            updateJournal();
+            return b;
+        }
+
+        /*@Override
         public Quest remove(final int index) {
             final Quest s = super.remove(index);
             updateJournal();
@@ -164,7 +172,7 @@ public class Quester implements Comparable<Quester> {
             final Quest s = super.set(index, element);
             updateJournal();
             return s;
-        }
+        }*/
     };
     protected ConcurrentHashMap<Quest, Long> completedTimes = new ConcurrentHashMap<Quest, Long>();
     protected ConcurrentHashMap<Quest, Integer> amountsCompleted = new ConcurrentHashMap<Quest, Integer>() {
@@ -321,11 +329,11 @@ public class Quester implements Comparable<Quester> {
         this.currentQuests = currentQuests;
     }
 
-    public LinkedList<Quest> getCompletedQuests() {
+    public ConcurrentSkipListSet<Quest> getCompletedQuests() {
         return completedQuests;
     }
 
-    public void setCompletedQuests(final LinkedList<Quest> completedQuests) {
+    public void setCompletedQuests(final ConcurrentSkipListSet<Quest> completedQuests) {
         this.completedQuests = completedQuests;
     }
 
diff --git a/main/src/main/java/me/blackvein/quests/listeners/CmdExecutor.java b/main/src/main/java/me/blackvein/quests/listeners/CmdExecutor.java
index 1a880df61..4c6ae3c3d 100644
--- a/main/src/main/java/me/blackvein/quests/listeners/CmdExecutor.java
+++ b/main/src/main/java/me/blackvein/quests/listeners/CmdExecutor.java
@@ -653,15 +653,17 @@ public class CmdExecutor implements CommandExecutor {
                 cs.sendMessage(ChatColor.DARK_PURPLE + Lang.get("none"));
             } else {
                 final StringBuilder completed = new StringBuilder(" ");
+                int index = 1;
                 for (final Quest q : quester.getCompletedQuests()) {
                     
                     completed.append(ChatColor.DARK_PURPLE + q.getName());
                     if (quester.getAmountsCompleted().containsKey(q) && quester.getAmountsCompleted().get(q) > 1) {
                         completed.append(ChatColor.LIGHT_PURPLE + " (x" + quester.getAmountsCompleted().get(q) + ")");
                     }
-                    if (quester.getCompletedQuests().indexOf(q) < (quester.getCompletedQuests().size() - 1)) {
+                    if (index < (quester.getCompletedQuests().size())) {
                         completed.append(", ");
                     }
+                    index++;
                 }
                 cs.sendMessage(completed.toString());
             }
diff --git a/main/src/main/java/me/blackvein/quests/storage/implementation/file/SeparatedYamlStorage.java b/main/src/main/java/me/blackvein/quests/storage/implementation/file/SeparatedYamlStorage.java
index 6feb121ad..3aecf96e8 100644
--- a/main/src/main/java/me/blackvein/quests/storage/implementation/file/SeparatedYamlStorage.java
+++ b/main/src/main/java/me/blackvein/quests/storage/implementation/file/SeparatedYamlStorage.java
@@ -118,7 +118,7 @@ public class SeparatedYamlStorage implements StorageImplementation {
         }
         quester.setLastKnownName(data.getString("lastKnownName"));
         quester.setQuestPoints(data.getInt("quest-points"));
-        final LinkedList<Quest> completedQuests = quester.getCompletedQuests();
+        final ConcurrentSkipListSet<Quest> completedQuests = quester.getCompletedQuests();
         if (data.isList("completed-Quests")) {
             for (final String s : data.getStringList("completed-Quests")) {
                 for (final Quest q : plugin.getQuests()) {
diff --git a/main/src/main/java/me/blackvein/quests/storage/implementation/sql/SqlStorage.java b/main/src/main/java/me/blackvein/quests/storage/implementation/sql/SqlStorage.java
index 582bff735..249a7fc45 100644
--- a/main/src/main/java/me/blackvein/quests/storage/implementation/sql/SqlStorage.java
+++ b/main/src/main/java/me/blackvein/quests/storage/implementation/sql/SqlStorage.java
@@ -18,7 +18,6 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.Collection;
-import java.util.LinkedList;
 import java.util.Map.Entry;
 import java.util.Set;
 import java.util.UUID;
@@ -322,8 +321,8 @@ public class SqlStorage implements StorageImplementation {
         return currentQuests;
     }
     
-    public LinkedList<Quest> getQuesterCompletedQuests(final UUID uniqueId) throws Exception {
-        final LinkedList<Quest> completedQuests = new LinkedList<Quest>();
+    public ConcurrentSkipListSet<Quest> getQuesterCompletedQuests(final UUID uniqueId) throws Exception {
+        final ConcurrentSkipListSet<Quest> completedQuests = new ConcurrentSkipListSet<Quest>();
         try (Connection c = connectionFactory.getConnection()) {
             try (PreparedStatement ps = c.prepareStatement(statementProcessor.apply(PLAYER_COMPLETED_QUESTS_SELECT_BY_UUID))) {
                 ps.setString(1, uniqueId.toString());