diff --git a/acl/aclbit.go b/acl/aclbit.go
index bad609e..1c3eb39 100644
--- a/acl/aclbit.go
+++ b/acl/aclbit.go
@@ -66,7 +66,7 @@ func Verify(a AclBit, n NumBit) bool {
 }
 
 // converting acl bits to string
-func String(a AclBit) string {
+func (a AclBit) String() string {
 	return strconv.FormatInt(int64(a), 2)
 }