diff --git a/params/config_classic.go b/params/config_classic.go
index e35441567d..ceba7d4ffe 100644
--- a/params/config_classic.go
+++ b/params/config_classic.go
@@ -94,12 +94,13 @@ var (
 		EIP3529FBlock: big.NewInt(14_525_000),
 		EIP3541FBlock: big.NewInt(14_525_000),
 
-		// EIP4399FBlock: big.NewInt(18_400_000), // Supplant DIFFICULTY with PREVRANDAO. ETC does not spec 4399 because it's still PoW, and 4399 is only applicable for the PoS system.
-		EIP3651FBlock: big.NewInt(18_400_000), // Warm COINBASE (gas reprice)
-		EIP3855FBlock: big.NewInt(18_400_000), // PUSH0 instruction
-		EIP3860FBlock: big.NewInt(18_400_000), // Limit and meter initcode
-		// EIP4895FBlock: big.NewInt(18_400_000), // Beacon chain push withdrawals as operations
-		EIP6049FBlock: big.NewInt(18_400_000), // Deprecate SELFDESTRUCT (noop)
+		// Spiral, aka Shanghai (partially)
+		// EIP4399FBlock: nil, // Supplant DIFFICULTY with PREVRANDAO. ETC does not spec 4399 because it's still PoW, and 4399 is only applicable for the PoS system.
+		EIP3651FBlock: nil, // Warm COINBASE (gas reprice)
+		EIP3855FBlock: nil, // PUSH0 instruction
+		EIP3860FBlock: nil, // Limit and meter initcode
+		// EIP4895FBlock: nil, // Beacon chain push withdrawals as operations
+		EIP6049FBlock: nil, // Deprecate SELFDESTRUCT (noop)
 
 		RequireBlockHashes: map[uint64]common.Hash{
 			1920000: common.HexToHash("0x94365e3a8c0b35089c1d1195081fe7489b528a84b22199c916180db8b28ade7f"),
diff --git a/params/config_mordor.go b/params/config_mordor.go
index 1540a1c689..a1dd40dc02 100644
--- a/params/config_mordor.go
+++ b/params/config_mordor.go
@@ -80,6 +80,14 @@ var (
 		EIP3529FBlock: big.NewInt(5_520_000),
 		EIP3541FBlock: big.NewInt(5_520_000),
 
+		// Spiral, aka Shanghai (partially)
+		// EIP4399FBlock: nil, // Supplant DIFFICULTY with PREVRANDAO. ETC does not spec 4399 because it's still PoW, and 4399 is only applicable for the PoS system.
+		EIP3651FBlock: nil, // Warm COINBASE (gas reprice)
+		EIP3855FBlock: nil, // PUSH0 instruction
+		EIP3860FBlock: nil, // Limit and meter initcode
+		// EIP4895FBlock: nil, // Beacon chain push withdrawals as operations
+		EIP6049FBlock: nil, // Deprecate SELFDESTRUCT (noop)
+
 		DisposalBlock:      big.NewInt(0),
 		ECIP1017FBlock:     big.NewInt(0),
 		ECIP1017EraRounds:  big.NewInt(2000000),