diff --git a/core/genesis.go b/core/genesis.go
index 00175513c2..47afbdd392 100644
--- a/core/genesis.go
+++ b/core/genesis.go
@@ -320,7 +320,7 @@ func DefaultGenesisBlock() *Genesis {
 		Nonce:      66,
 		ExtraData:  hexutil.MustDecode("0x11bbe8db4e347b4e8c937c1c8370e4b5ed33adb3db69cbdb7a38e1e50b1b82fa"),
 		GasLimit:   5000,
-		Difficulty: big.NewInt(17179869184),
+		Difficulty: big.NewInt(1),
 		Alloc:      GenesisAlloc{
 				addr1: {Balance: big.NewInt(50000000000000000000)},
 				addr2: {Balance: big.NewInt(20000000000000000000)},
@@ -335,7 +335,7 @@ func DefaultTestnetGenesisBlock() *Genesis {
 		Nonce:      66,
 		ExtraData:  hexutil.MustDecode("0x3535353535353535353535353535353535353535353535353535353535353535"),
 		GasLimit:   16777216,
-		Difficulty: big.NewInt(1048576),
+		Difficulty: big.NewInt(1),
 		Alloc:      decodePrealloc(testnetAllocData),
 	}
 }