diff --git a/telegrambots/src/main/java/org/telegram/telegrambots/updatesreceivers/DefaultBotSession.java b/telegrambots/src/main/java/org/telegram/telegrambots/updatesreceivers/DefaultBotSession.java
index fec34b3e..b7d7140a 100644
--- a/telegrambots/src/main/java/org/telegram/telegrambots/updatesreceivers/DefaultBotSession.java
+++ b/telegrambots/src/main/java/org/telegram/telegrambots/updatesreceivers/DefaultBotSession.java
@@ -60,42 +60,42 @@ public class DefaultBotSession implements BotSession {
     }
 
     @Override
-    public synchronized void start() {
-        if (running.get()) {
+    public void start() {
+        if (running.compareAndSet(false, true)) {
             throw new IllegalStateException("Session already running");
         }
 
-        running.set(true);
+        synchronized (this) {
+            lastReceivedUpdate = 0;
 
-        lastReceivedUpdate = 0;
+            readerThread = new ReaderThread(updatesSupplier, this);
+            readerThread.setName(callback.getBotUsername() + " Telegram Connection");
+            readerThread.start();
 
-        readerThread = new ReaderThread(updatesSupplier, this);
-        readerThread.setName(callback.getBotUsername() + " Telegram Connection");
-        readerThread.start();
-
-        handlerThread = new HandlerThread();
-        handlerThread.setName(callback.getBotUsername() + " Telegram Executor");
-        handlerThread.start();
+            handlerThread = new HandlerThread();
+            handlerThread.setName(callback.getBotUsername() + " Telegram Executor");
+            handlerThread.start();
+        }
     }
 
     @Override
-    public synchronized void stop() {
-        if (!running.get()) {
+    public void stop() {
+        if (!running.compareAndSet(true, false)) {
             throw new IllegalStateException("Session already stopped");
         }
+        synchronized (this) {
 
-        running.set(false);
+            if (readerThread != null) {
+                readerThread.interrupt();
+            }
 
-        if (readerThread != null) {
-            readerThread.interrupt();
-        }
+            if (handlerThread != null) {
+                handlerThread.interrupt();
+            }
 
-        if (handlerThread != null) {
-            handlerThread.interrupt();
-        }
-
-        if (callback != null) {
-            callback.onClosing();
+            if (callback != null) {
+                callback.onClosing();
+            }
         }
     }