playdate.timer.timerEndedArgs overrides arguments to timer.updateCallback

I was experimenting with SDK version 1.9.1 (132837) on MacOS and encountered an issue where timer.timerEndedArgs overrides the arguments to timer.updateCallback, not just timer.timerEndedCallback.

I expected the updateCallback to receive the normal argument (just the timer itself) but it only gets the arguments I specified as timerEndedArguments.

The following minimal program will dump the arguments passed to the update callback to the simulator's console:

import "CoreLibs/object"
import "CoreLibs/timer"

local t =, 10, 150)

t.timerEndedArgs = {1, 2, 3}
t.updateCallback = function(tm, tm2, tm3)
	printTable(tm, tm2, tm3)
	playdate.update = function() end

function playdate.update()

You'll see 1 2 3 rather than the dumped timer table.