diff --git a/src/main/java/it/tdlight/common/InternalClient.java b/src/main/java/it/tdlight/common/InternalClient.java
index 94cd91f..d56dbc5 100644
--- a/src/main/java/it/tdlight/common/InternalClient.java
+++ b/src/main/java/it/tdlight/common/InternalClient.java
@@ -7,10 +7,11 @@ import it.tdlight.jni.TdApi.Update;
 import it.unimi.dsi.fastutil.longs.LongArrayList;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 public class InternalClient implements ClientEventsHandler, TelegramClient {
 
-	static final java.lang.Object CLIENT_CREATION_LOCK = new java.lang.Object();
+	static final ReentrantReadWriteLock clientInitializationLock = new ReentrantReadWriteLock(true);
 	private final ConcurrentHashMap<Long, Handler> handlers = new ConcurrentHashMap<Long, Handler>();
 
 	private final int clientId;
@@ -25,7 +26,8 @@ public class InternalClient implements ClientEventsHandler, TelegramClient {
 			ResultHandler updateHandler,
 			ExceptionHandler updateExceptionHandler,
 			ExceptionHandler defaultExceptionHandler) {
-		synchronized (CLIENT_CREATION_LOCK) {
+		clientInitializationLock.writeLock().lock();
+		try {
 			this.updateHandler = new Handler(updateHandler, updateExceptionHandler);
 			this.updatesHandler = null;
 			this.defaultExceptionHandler = defaultExceptionHandler;
@@ -33,6 +35,8 @@ public class InternalClient implements ClientEventsHandler, TelegramClient {
 			this.clientId = NativeClientAccess.create();
 
 			clientManager.registerClient(clientId, this);
+		} finally {
+			clientInitializationLock.writeLock().unlock();
 		}
 	}
 
@@ -40,7 +44,8 @@ public class InternalClient implements ClientEventsHandler, TelegramClient {
 			UpdatesHandler updatesHandler,
 			ExceptionHandler updateExceptionHandler,
 			ExceptionHandler defaultExceptionHandler) {
-		synchronized (CLIENT_CREATION_LOCK) {
+		clientInitializationLock.writeLock().lock();
+		try {
 			this.updateHandler = null;
 			this.updatesHandler = new MultiHandler(updatesHandler, updateExceptionHandler);
 			this.clientManager = clientManager;
@@ -48,6 +53,8 @@ public class InternalClient implements ClientEventsHandler, TelegramClient {
 			this.clientId = NativeClientAccess.create();
 
 			clientManager.registerClient(clientId, this);
+		} finally {
+			clientInitializationLock.writeLock().unlock();
 		}
 	}
 
diff --git a/src/main/java/it/tdlight/common/ResponseReceiver.java b/src/main/java/it/tdlight/common/ResponseReceiver.java
index bfeca2e..2e6071b 100644
--- a/src/main/java/it/tdlight/common/ResponseReceiver.java
+++ b/src/main/java/it/tdlight/common/ResponseReceiver.java
@@ -1,6 +1,6 @@
 package it.tdlight.common;
 
-import static it.tdlight.common.InternalClient.CLIENT_CREATION_LOCK;
+import static it.tdlight.common.InternalClient.clientInitializationLock;
 
 import it.tdlight.jni.TdApi;
 import it.tdlight.jni.TdApi.Object;
@@ -49,8 +49,11 @@ public class ResponseReceiver extends Thread implements AutoCloseable {
 		try {
 			while(true) {
 				int resultsCount;
-				synchronized (CLIENT_CREATION_LOCK) {
+				clientInitializationLock.readLock().lock();
+				try {
 					resultsCount = NativeClientAccess.receive(clientIds, eventIds, events, 2.0 /*seconds*/);
+				} finally {
+					clientInitializationLock.readLock().unlock();
 				}
 
 				if (resultsCount <= 0)