diff --git a/common/math/big.go b/common/math/big.go
index 5f62b010fa..fd0174b366 100644
--- a/common/math/big.go
+++ b/common/math/big.go
@@ -27,8 +27,8 @@ var (
 	tt256     = BigPow(2, 256)
 	tt256m1   = new(big.Int).Sub(tt256, big.NewInt(1))
 	MaxBig256 = new(big.Int).Set(tt256m1)
-	tt63      = BigPow(2,63)
-	TT63m1    = new(big.Int).Sub(tt63,big.NewInt(1))
+	tt63      = BigPow(2, 63)
+	MaxBig63  = new(big.Int).Sub(tt63, big.NewInt(1))
 )
 
 const (
diff --git a/consensus/ethash/consensus.go b/consensus/ethash/consensus.go
index f461fabd6b..cc8413482d 100644
--- a/consensus/ethash/consensus.go
+++ b/consensus/ethash/consensus.go
@@ -244,12 +244,12 @@ func (ethash *Ethash) verifyHeader(chain consensus.ChainReader, header, parent *
 		return fmt.Errorf("invalid difficulty: have %v, want %v", header.Difficulty, expected)
 	}
 	// Verify that the gas limit is < 2^63-1
-	if header.GasLimit.Cmp(math.TT63m1) > 0{
-		return fmt.Errorf("invalid gasLimit: have %v, max %v", header.GasLimit, math.TT63m1)	
+	if header.GasLimit.Cmp(math.MaxBig63) > 0 {
+		return fmt.Errorf("invalid gasLimit: have %v, max %v", header.GasLimit, math.MaxBig63)
 	}
 	// Verify that the gasUsed is <= gasLimit
-	if header.GasUsed.Cmp(header.GasLimit) > 0{
-		return fmt.Errorf("invalid gasUsed: have %v, gasLimit %v", header.GasUsed, header.GasLimit)			
+	if header.GasUsed.Cmp(header.GasLimit) > 0 {
+		return fmt.Errorf("invalid gasUsed: have %v, gasLimit %v", header.GasUsed, header.GasLimit)
 	}
 
 	// Verify that the gas limit remains within allowed bounds