diff --git a/build/params_testground.go b/build/params_testground.go
index 704503981..1b81ebae3 100644
--- a/build/params_testground.go
+++ b/build/params_testground.go
@@ -29,7 +29,7 @@ var (
 
 	AllowableClockDriftSecs = uint64(1)
 
-	Finality            = miner.ChainFinalityish
+	Finality            = miner.ChainFinality
 	ForkLengthThreshold = Finality
 
 	SlashablePowerDelay        = 20