diff --git a/accounts/keystore/keystore.go b/accounts/keystore/keystore.go
index 47fa376ed8..f791ad0b3e 100644
--- a/accounts/keystore/keystore.go
+++ b/accounts/keystore/keystore.go
@@ -495,8 +495,5 @@ func (ks *KeyStore) ImportPreSaleKey(keyJSON []byte, passphrase string) (account
 
 // zeroKey zeroes a private key in memory.
 func zeroKey(k *ecdsa.PrivateKey) {
-	b := k.D.Bits()
-	for i := range b {
-		b[i] = 0
-	}
+	k.D.SetUint64(uint64(0))
 }