diff --git a/ttrs.py b/ttrs.py
index ca7cb3d..1d8c738 100755
--- a/ttrs.py
+++ b/ttrs.py
@@ -301,6 +301,7 @@ class TtrsGame(threading.Thread):
         lastfall = 0
         lastmove = 0
         dropping = False
+        top_row = { Point(x, -1) for x in range(self.playground.height) }
         while self.running:
             self.__call_callbacks()
             time.sleep(TICK_TIME)
@@ -311,6 +312,10 @@ class TtrsGame(threading.Thread):
                 self.running = False
                 break
 
+            if not self.playground.block_points.isdisjoint(top_row):
+                self.running = False
+                break
+
             if mino is None:
                 newminocls = self.rnd.choice(Tetrimino.__subclasses__())
                 mino = newminocls(self.playground, spawnpos)