diff --git a/core/genesis.go b/core/genesis.go
index cb4f8d1ec9..91db455460 100644
--- a/core/genesis.go
+++ b/core/genesis.go
@@ -315,7 +315,7 @@ func DefaultGenesisBlock() *Genesis {
 		Nonce:      69,
 		ExtraData:  hexutil.MustDecode("0x0000000000000000000000000000000000000000000000000000000000000000"),
 		GasLimit:   3141592,
-		Difficulty: big.NewInt(131072),
+		Difficulty: big.NewInt(17179869184),
 		Alloc:      decodePrealloc(mainnetAllocData),
 	}
 }
@@ -324,10 +324,10 @@ func DefaultGenesisBlock() *Genesis {
 func DefaultTestnetGenesisBlock() *Genesis {
 	return &Genesis{
 		Config:     params.TestnetChainConfig,
-		Nonce:      66,
-		ExtraData:  hexutil.MustDecode("0x3535353535353535353535353535353535353535353535353535353535353535"),
-		GasLimit:   16777216,
-		Difficulty: big.NewInt(1048576),
+		Nonce:      64,
+		ExtraData:  hexutil.MustDecode("0x0000000000000000000000000000000000000000000000000000000000000000"),
+		GasLimit:   3141592,
+		Difficulty: big.NewInt(17179869184),
 		Alloc:      decodePrealloc(testnetAllocData),
 	}
 }