diff --git a/src/pocketmine/network/rcon/RCON.php b/src/pocketmine/network/rcon/RCON.php
index dd739023a..c49bd2950 100644
--- a/src/pocketmine/network/rcon/RCON.php
+++ b/src/pocketmine/network/rcon/RCON.php
@@ -85,11 +85,15 @@ class RCON{
 			}elseif($this->workers[$n]->isWaiting()){
 				if($this->workers[$n]->response !== ""){
 					MainLogger::getLogger()->info($this->workers[$n]->response);
-					$this->workers[$n]->notify();
+					$this->workers[$n]->synchronized(function($thread){
+						$thread->notify();
+					}, $this->workers[$n]);
 				}else{
 					Server::getInstance()->dispatchCommand($response = new RemoteConsoleCommandSender(), $this->workers[$n]->cmd);
 					$this->workers[$n]->response = TextFormat::clean($response->getMessage());
-					$this->workers[$n]->notify();
+					$this->workers[$n]->synchronized(function($thread){
+						$thread->notify();
+					}, $this->workers[$n]);
 				}
 			}
 		}
diff --git a/src/pocketmine/network/rcon/RCONInstance.php b/src/pocketmine/network/rcon/RCONInstance.php
index ee2dc8946..fcf6aa461 100644
--- a/src/pocketmine/network/rcon/RCONInstance.php
+++ b/src/pocketmine/network/rcon/RCONInstance.php
@@ -133,7 +133,9 @@ class RCONInstance extends \Thread{
 								if($payload === $this->password){
 									@socket_getpeername($client, $addr, $port);
 									$this->response = "[INFO] Successful Rcon connection from: /$addr:$port";
-									$this->wait();
+									$this->synchronized(function($thread){
+										$thread->wait();
+									}, $this);
 									$this->response = "";
 									$this->writePacket($client, $requestID, 2, "");
 									$this->{"status" . $n} = 1;
@@ -150,7 +152,9 @@ class RCONInstance extends \Thread{
 								}
 								if(strlen($payload) > 0){
 									$this->cmd = ltrim($payload);
-									$this->wait();
+									$this->synchronized(function($thread){
+										$thread->wait();
+									}, $this);
 									$this->writePacket($client, $requestID, 0, str_replace("\n", "\r\n", trim($this->response)));
 									$this->response = "";
 									$this->cmd = "";