diff --git a/tetris/modes/square.lua b/tetris/modes/square.lua
index 4b01fc0..06fa2fc 100644
--- a/tetris/modes/square.lua
+++ b/tetris/modes/square.lua
@@ -38,8 +38,7 @@ function SquareMode:getGravity()
 end
 
 function SquareMode:getLockDelay()
-    if self:getGravity() <= 20 then return 30
-    else return 30 - math.log(self:getGravity() - 20) end
+    return math.ceil(30 * 0.9998 ^ self.lines)
 end
 
 function SquareMode:advanceOneFrame()
@@ -97,4 +96,4 @@ function SquareMode:getBackground()
     return math.floor(self.lines / 100) % 20
 end
 
-return SquareMode
\ No newline at end of file
+return SquareMode