diff --git a/src/gui/__init__.py b/src/gui/__init__.py
--- a/src/gui/__init__.py
+++ b/src/gui/__init__.py
@@ -37,7 +37,7 @@ class GUI:
 		self.root.bind("<<setUp>>", lambda e: self.setUp())
 		self.root.bind("<<setRecording>>", lambda e: self.setRecording())
 		self.root.bind("<F12>",lambda e: Settings(self))
-		self.mainWindow.bind("<Destroy>",lambda e: self._ownMessages.send("!kill",("gui",)))
+		self.mainWindow.bind("<Destroy>",lambda e: self._shutDown())
 
 		self.setUp()
 
@@ -45,8 +45,8 @@ class GUI:
 		self._ownMessages=ownMessages
 		self._coreMessages=coreMessages
 
-		self.listenerThread=threading.Thread(target=lambda: ownMessages.listen(self._handleEvent))
-		self.listenerThread.start()
+		self._listenerThread=threading.Thread(target=lambda: ownMessages.listen(self._handleEvent))
+		self._listenerThread.start()
 
 		self.mainWindow.mainloop()
 
@@ -70,6 +70,11 @@ class GUI:
 	def sendParams(self):
 		self.sendMsg("setParams",(self.detector.params.copy(),))
 
+	def _shutDown(self):
+		log.info("GUI proc exiting.")
+		self._ownMessages.send("!kill",("gui",))
+		self._listenerThread.join()
+
 	def _handleEvent(self,e):
 		actions={
 			"setFrame": self._frameHandler,