diff --git a/src/jthread/jthread.h b/src/jthread/jthread.h
index 92b05f1c..867701c7 100644
--- a/src/jthread/jthread.h
+++ b/src/jthread/jthread.h
@@ -47,6 +47,7 @@ public:
 	int Kill();
 	virtual void *Thread() = 0;
 	bool IsRunning();
+	bool StopRequested();
 	void *GetReturnValue();
 	bool IsSameThread();
 protected:
@@ -69,6 +70,7 @@ private:
 #endif // WIN32
 	void *retval;
 	bool running;
+	bool requeststop;
 
 	JMutex runningmutex;
 	JMutex continuemutex,continuemutex2;
diff --git a/src/jthread/pthread/jthread.cpp b/src/jthread/pthread/jthread.cpp
index 2980e26b..c4d9162c 100644
--- a/src/jthread/pthread/jthread.cpp
+++ b/src/jthread/pthread/jthread.cpp
@@ -34,6 +34,7 @@ JThread::JThread()
 {
 	retval = NULL;
 	mutexinit = false;
+	requeststop = false;
 	running = false;
 }
 
@@ -44,7 +45,7 @@ JThread::~JThread()
 
 void JThread::Stop() {
 	runningmutex.Lock();
-	running = false;
+	requeststop = true;
 	runningmutex.Unlock();
 }
 
@@ -78,6 +79,7 @@ int JThread::Start()
 		runningmutex.Unlock();
 		return ERR_JTHREAD_ALREADYRUNNING;
 	}
+	requeststop = false;
 	runningmutex.Unlock();
 
 	pthread_attr_t attr;
@@ -141,6 +143,15 @@ bool JThread::IsRunning()
 	return r;
 }
 
+bool JThread::StopRequested() {
+	bool r;
+
+	runningmutex.Lock();
+	r = requeststop;
+	runningmutex.Unlock();
+	return r;
+}
+
 void *JThread::GetReturnValue()
 {
 	void *val;
diff --git a/src/jthread/win32/jthread.cpp b/src/jthread/win32/jthread.cpp
index 1cf4f93a..e56c1627 100644
--- a/src/jthread/win32/jthread.cpp
+++ b/src/jthread/win32/jthread.cpp
@@ -35,6 +35,7 @@ JThread::JThread()
 {
 	retval = NULL;
 	mutexinit = false;
+	requeststop = false;
 	running = false;
 }
 
@@ -45,7 +46,7 @@ JThread::~JThread()
 
 void JThread::Stop() {
 	runningmutex.Lock();
-	running = false;
+	requeststop = false;
 	runningmutex.Unlock();
 }
 
@@ -76,6 +77,7 @@ int JThread::Start()
 		runningmutex.Unlock();
 		return ERR_JTHREAD_ALREADYRUNNING;
 	}
+	requeststop = false;e
 	runningmutex.Unlock();
 
 	continuemutex.Lock();
@@ -134,6 +136,15 @@ bool JThread::IsRunning()
 	return r;
 }
 
+bool JThread::StopRequested() {
+	bool r;
+
+	runningmutex.Lock();
+	r = requeststop;
+	runningmutex.Unlock();
+	return r;
+}
+
 void *JThread::GetReturnValue()
 {
 	void *val;
diff --git a/src/script/lua_api/l_async_events.cpp b/src/script/lua_api/l_async_events.cpp
index cc4644cd..63ca87ae 100644
--- a/src/script/lua_api/l_async_events.cpp
+++ b/src/script/lua_api/l_async_events.cpp
@@ -149,9 +149,11 @@ LuaJobInfo AsyncEngine::getJob() {
 	m_JobQueueMutex.Lock();
 
 	LuaJobInfo retval;
+	retval.valid = false;
 
 	if (m_JobQueue.size() != 0) {
 		retval = m_JobQueue.front();
+		retval.valid = true;
 		m_JobQueue.erase((m_JobQueue.begin()));
 	}
 	m_JobQueueMutex.Unlock();
@@ -322,11 +324,12 @@ void* AsyncWorkerThread::worker_thread_main() {
 			assert("no future with broken builtin async environment scripts" == 0);
 	}
 	/** main loop **/
-	while(IsRunning()) {
+	while(!StopRequested()) {
 		//wait for job
 		LuaJobInfo toprocess = m_JobDispatcher->getJob();
 
-		if (!IsRunning()) { continue; }
+		if (toprocess.valid == false) { continue; }
+		if (StopRequested()) { continue; }
 
 		//first push error handler
 		lua_pushcfunction(m_LuaStack, script_error_handler);
@@ -350,7 +353,7 @@ void* AsyncWorkerThread::worker_thread_main() {
 						toprocess.serializedParams.c_str(),
 						toprocess.serializedParams.length());
 
-		if (!IsRunning()) { continue; }
+		if (StopRequested()) { continue; }
 		if(lua_pcall(m_LuaStack, 2, 2, errorhandler)) {
 			scriptError("Async WORKER thread: %s\n", lua_tostring(m_LuaStack, -1));
 			toprocess.serializedResult="ERROR";
@@ -362,7 +365,7 @@ void* AsyncWorkerThread::worker_thread_main() {
 			toprocess.serializedResult = std::string(retval,lenght);
 		}
 
-		if (!IsRunning()) { continue; }
+		if (StopRequested()) { continue; }
 		//put job result
 		m_JobDispatcher->putJobResult(toprocess);
 	}
diff --git a/src/script/lua_api/l_async_events.h b/src/script/lua_api/l_async_events.h
index 347d9c0f..079a0800 100644
--- a/src/script/lua_api/l_async_events.h
+++ b/src/script/lua_api/l_async_events.h
@@ -57,6 +57,8 @@ struct LuaJobInfo {
 	std::string serializedResult;
 	/** jobid used to identify a job and match it to callback **/
 	unsigned int JobId;
+	/** valid marker **/
+	bool valid;
 };
 
 /** class encapsulating a asynchronous working environment **/