diff --git a/params/config_classic.go b/params/config_classic.go
index 30a271a909..dfaa98f128 100644
--- a/params/config_classic.go
+++ b/params/config_classic.go
@@ -75,7 +75,7 @@ var (
 		ECIP1017EraRounds:  big.NewInt(5000000),
 		ECIP1010PauseBlock: big.NewInt(3000000),
 		ECIP1010Length:     big.NewInt(2000000),
-		ECBP1100FBlock:     big.NewInt(11_317_400), // ETA 1 October 2020
+		ECBP1100FBlock:     nil, // TODO@ethereumclassic/ECIPS
 		RequireBlockHashes: map[uint64]common.Hash{
 			1920000: common.HexToHash("0x94365e3a8c0b35089c1d1195081fe7489b528a84b22199c916180db8b28ade7f"),
 			2500000: common.HexToHash("0xca12c63534f565899681965528d536c52cb05b7c48e269c2a6cb77ad864d878a"),
diff --git a/params/config_mordor.go b/params/config_mordor.go
index 1198de55ac..195873934b 100644
--- a/params/config_mordor.go
+++ b/params/config_mordor.go
@@ -71,7 +71,7 @@ var (
 		ECIP1017EraRounds:  big.NewInt(2000000),
 		ECIP1010PauseBlock: nil,
 		ECIP1010Length:     nil,
-		ECBP1100FBlock:     big.NewInt(2290740), // ETA 15 Sept 2020, ~1500 UTC
+		ECBP1100FBlock:     big.NewInt(2380000), // ETA 15 Sept 2020, ~1500 UTC
 		RequireBlockHashes: map[uint64]common.Hash{
 			840013: common.HexToHash("0x2ceada2b191879b71a5bcf2241dd9bc50d6d953f1640e62f9c2cee941dc61c9d"),
 			840014: common.HexToHash("0x8ec29dd692c8985b82410817bac232fc82805b746538d17bc924624fe74a0fcf"),