diff --git a/testnet/testchain.json b/testnet/testchain.json
index 3b31c3e3..089bd693 100644
--- a/testnet/testchain.json
+++ b/testnet/testchain.json
@@ -26,6 +26,7 @@
 	"onlineAccountSignaturesMaxLifetime": 86400000,
 	"onlineAccountsModulusV2Timestamp": 0,
 	"selfSponsorshipAlgoV1SnapshotTimestamp": 9999999999999,
+	"mempowTransactionUpdatesTimestamp": 1692554400000,
 	"rewardsByHeight": [
 		{ "height": 1, "reward": 5.00 },
 		{ "height": 259201, "reward": 4.75 },