diff --git a/common/bytes.go b/common/bytes.go
index c82e616241..b1cca130af 100644
--- a/common/bytes.go
+++ b/common/bytes.go
@@ -43,10 +43,8 @@ func ToHexArray(b [][]byte) []string {
 // FromHex returns the bytes represented by the hexadecimal string s.
 // s may be prefixed with "0x".
 func FromHex(s string) []byte {
-	if len(s) > 1 {
-		if s[0:2] == "0x" || s[0:2] == "0X" {
-			s = s[2:]
-		}
+	if hasHexPrefix(s) {
+		s = s[2:]
 	}
 	if len(s)%2 == 1 {
 		s = "0" + s