diff --git a/Tasks/src/main/java/fr/altarik/toolbox/task/async/AsyncPeriodicTasks.java b/Tasks/src/main/java/fr/altarik/toolbox/task/async/AsyncPeriodicTasks.java
index 46262b1..1141751 100644
--- a/Tasks/src/main/java/fr/altarik/toolbox/task/async/AsyncPeriodicTasks.java
+++ b/Tasks/src/main/java/fr/altarik/toolbox/task/async/AsyncPeriodicTasks.java
@@ -2,7 +2,6 @@ package fr.altarik.toolbox.task.async;
 
 import fr.altarik.toolbox.task.AltarikRunnable;
 import fr.altarik.toolbox.task.PeriodicTaskI;
-import fr.altarik.toolbox.task.TaskI;
 import it.unimi.dsi.fastutil.ints.IntComparators;
 
 import java.util.ArrayList;
@@ -48,11 +47,11 @@ public class AsyncPeriodicTasks implements PeriodicTaskI, AsyncTaskI {
      *
      * @return an instance of AsyncTasks
      */
-    public static TaskI initialize(int numberOfWorker) {
+    public static PeriodicTaskI initialize(int numberOfWorker) {
         return new AsyncPeriodicTasks(numberOfWorker);
     }
 
-    public static TaskI initialize() {
+    public static PeriodicTaskI initialize() {
         return initialize(Runtime.getRuntime().availableProcessors());
     }
 
diff --git a/Tasks/src/main/java/fr/altarik/toolbox/task/async/TaskScheduler.java b/Tasks/src/main/java/fr/altarik/toolbox/task/async/TaskScheduler.java
index 04358ae..4bc2e74 100644
--- a/Tasks/src/main/java/fr/altarik/toolbox/task/async/TaskScheduler.java
+++ b/Tasks/src/main/java/fr/altarik/toolbox/task/async/TaskScheduler.java
@@ -30,7 +30,6 @@ public class TaskScheduler {
      */
     public synchronized void asyncRunnerPeriodicTasks() throws InterruptedException {
         loop: while(true) {
-            notify();
             while(asyncTasks.size() == 0) {
                 if(isStop()) {
                     break loop;
diff --git a/Tasks/src/main/java/fr/altarik/toolbox/task/sync/PeriodicSyncTask.java b/Tasks/src/main/java/fr/altarik/toolbox/task/sync/PeriodicSyncTask.java
index 25d2e10..381c263 100644
--- a/Tasks/src/main/java/fr/altarik/toolbox/task/sync/PeriodicSyncTask.java
+++ b/Tasks/src/main/java/fr/altarik/toolbox/task/sync/PeriodicSyncTask.java
@@ -24,7 +24,7 @@ public class PeriodicSyncTask implements PeriodicTaskI, Runnable {
 
     @Override
     public void addTask(AltarikRunnable function) {
-        addTask(function, 0, 0);
+        addTask(function, 0, 1);
     }
 
     @Override
@@ -51,6 +51,6 @@ public class PeriodicSyncTask implements PeriodicTaskI, Runnable {
 
     @Override
     public void addTask(AltarikRunnable function, long delay, long period) {
-        tasks.add(new SchedulerTaskData(function, delay, period));
+        tasks.add(new SchedulerTaskData(function, delay, period - 1));
     }
 }
diff --git a/Tasks/src/main/java/fr/altarik/toolbox/task/sync/OneTimeSyncTask.java b/Tasks/src/main/java/fr/altarik/toolbox/task/sync/SyncTask.java
similarity index 91%
rename from Tasks/src/main/java/fr/altarik/toolbox/task/sync/OneTimeSyncTask.java
rename to Tasks/src/main/java/fr/altarik/toolbox/task/sync/SyncTask.java
index 0beeda1..749fe0c 100644
--- a/Tasks/src/main/java/fr/altarik/toolbox/task/sync/OneTimeSyncTask.java
+++ b/Tasks/src/main/java/fr/altarik/toolbox/task/sync/SyncTask.java
@@ -7,18 +7,18 @@ import fr.altarik.toolbox.task.TaskI;
 import java.util.ArrayList;
 import java.util.List;
 
-public class OneTimeSyncTask implements TaskI, Runnable {
+public class SyncTask implements TaskI, Runnable {
 
     private final ServerTickListener listener;
     private final List<SchedulerTaskData> tasks;
 
-    private OneTimeSyncTask() {
+    private SyncTask() {
         this.listener = new ServerTickListener(this);
         this.tasks = new ArrayList<>(2);
     }
 
     public static TaskI initialize() {
-        return new OneTimeSyncTask();
+        return new SyncTask();
     }
 
     @Override
diff --git a/Tasks/src/test/java/fr/altarik/toolbox/task/async/PeriodicAsyncTaskTest.java b/Tasks/src/test/java/fr/altarik/toolbox/task/async/PeriodicAsyncTaskTest.java
new file mode 100644
index 0000000..29e0fe6
--- /dev/null
+++ b/Tasks/src/test/java/fr/altarik/toolbox/task/async/PeriodicAsyncTaskTest.java
@@ -0,0 +1,32 @@
+package fr.altarik.toolbox.task.async;
+
+import fr.altarik.toolbox.task.AltarikRunnable;
+import org.junit.jupiter.api.Test;
+
+import java.util.Stack;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class PeriodicAsyncTaskTest {
+
+    @Test
+    void testPeriodicASyncTask() {
+        AsyncPeriodicTasks worker = (AsyncPeriodicTasks) AsyncPeriodicTasks.initialize();
+        Stack<AtomicInteger> results = new Stack<>();
+        AtomicInteger value1 = new AtomicInteger(1);
+        AtomicInteger value2 = new AtomicInteger(2);
+        AltarikRunnable runnable1 = new AltarikRunnable() {
+            @Override
+            public void run() {
+                results.add(value1);
+            }
+        };
+        AltarikRunnable runnable2 = new AltarikRunnable() {
+            @Override
+            public void run() {
+                results.add(value2);
+            }
+        };
+
+
+    }
+}
diff --git a/Tasks/src/test/java/fr/altarik/toolbox/task/sync/OneTimeSyncTaskTest.java b/Tasks/src/test/java/fr/altarik/toolbox/task/sync/OneTimeSyncTaskTest.java
deleted file mode 100644
index e9e8a1f..0000000
--- a/Tasks/src/test/java/fr/altarik/toolbox/task/sync/OneTimeSyncTaskTest.java
+++ /dev/null
@@ -1,25 +0,0 @@
-package fr.altarik.toolbox.task.sync;
-
-import fr.altarik.toolbox.task.AltarikRunnable;
-import org.junit.jupiter.api.Test;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.atomic.AtomicInteger;
-
-public class OneTimeSyncTaskTest {
-
-    @Test
-    void testOneTimeTask() {
-        OneTimeSyncTask worker = (OneTimeSyncTask) OneTimeSyncTask.initialize();
-        List<AtomicInteger> results = new ArrayList<>();
-        AtomicInteger value1 = new AtomicInteger(1);
-        AtomicInteger value2 = new AtomicInteger(2);
-        worker.addTask(new AltarikRunnable() {
-            @Override
-            public void run() {
-                results.add(value1);
-            }
-        });
-    }
-}
diff --git a/Tasks/src/test/java/fr/altarik/toolbox/task/sync/PeriodicSyncTaskTest.java b/Tasks/src/test/java/fr/altarik/toolbox/task/sync/PeriodicSyncTaskTest.java
index b5d0a90..2a5565c 100644
--- a/Tasks/src/test/java/fr/altarik/toolbox/task/sync/PeriodicSyncTaskTest.java
+++ b/Tasks/src/test/java/fr/altarik/toolbox/task/sync/PeriodicSyncTaskTest.java
@@ -8,7 +8,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicInteger;
 
-public class PeriodicSyncTaskTest {
+class PeriodicSyncTaskTest {
 
     @Test
     void testPeriodicSyncTask() {
@@ -22,7 +22,7 @@ public class PeriodicSyncTaskTest {
             public void run() {
                 results.add(value1);
             }
-        }, 1, 2);
+        }, 1, 3);
         worker.addTask(new AltarikRunnable() {
             private int i = 0;
             @Override
diff --git a/Tasks/src/test/java/fr/altarik/toolbox/task/sync/SyncTaskTest.java b/Tasks/src/test/java/fr/altarik/toolbox/task/sync/SyncTaskTest.java
new file mode 100644
index 0000000..b700843
--- /dev/null
+++ b/Tasks/src/test/java/fr/altarik/toolbox/task/sync/SyncTaskTest.java
@@ -0,0 +1,49 @@
+package fr.altarik.toolbox.task.sync;
+
+import fr.altarik.toolbox.task.AltarikRunnable;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+
+class SyncTaskTest {
+
+    @Test
+    void testOneTimeTask() {
+        SyncTask worker = (SyncTask) SyncTask.initialize();
+        List<AtomicInteger> results = new ArrayList<>();
+        AtomicInteger value1 = new AtomicInteger(1);
+        AtomicInteger value2 = new AtomicInteger(2);
+        AltarikRunnable task1 = new AltarikRunnable() {
+            @Override
+            public void run() {
+                results.add(value1);
+            }
+        };
+        AltarikRunnable task2 = new AltarikRunnable() {
+            @Override
+            public void run() {
+                results.add(value2);
+            }
+        };
+        worker.addTask(task1);
+        worker.run();
+        worker.run();
+        worker.addTask(task2);
+        worker.addTask(task1);
+        worker.addTask(task2);
+        worker.run();
+        worker.addTask(task1);
+        worker.run();
+        AtomicInteger[] expected = {
+                value1,
+                value2,
+                value1,
+                value2,
+                value1
+        };
+        Assertions.assertArrayEquals(expected, results.toArray());
+    }
+}