diff --git a/maps.py b/maps.py
index c30b09c..0cbdbda 100644
--- a/maps.py
+++ b/maps.py
@@ -211,7 +211,8 @@ class Map():
 		#self.load_visible()
 	
 	def apply_changes(self, changes):
-		self.chunkpool.apply_changes(changes)
+		with self.chunkpool as pool:
+			pool.apply_changes(changes)
 
 ChunkStyle = namedtuple("ChunkStyle", "string color")
 
diff --git a/server.py b/server.py
index 41c6fb2..f5c4cdd 100644
--- a/server.py
+++ b/server.py
@@ -27,8 +27,9 @@ class WotServer(WebSocket):
 	
 	def handle_unload_chunks(self, coords):
 		for coor in coords:
-			pos = Position(coor)
-			self.loaded_chunks.remove(pos)
+			pos = Position(coor[0], coor[1])
+			if pos in self.loaded_chunks:
+				self.loaded_chunks.remove(pos)
 	
 	def handle_save_changes(self, dchanges):
 		changes = []