diff --git a/tetris/modes/combo_challenge.lua b/tetris/modes/combo_challenge.lua
index cf4a3e4..eb8b0de 100644
--- a/tetris/modes/combo_challenge.lua
+++ b/tetris/modes/combo_challenge.lua
@@ -45,6 +45,7 @@ function ComboChallenge:new()
     GameMode:new()
     self.grid = Grid(4, 24)
     self.grid:applyMap(maps[math.random(#maps)])
+    self.randomizer = BagRandomizer()
     self.lock_drop = false
     self.lock_hard_drop = false
     self.enable_hold = true