diff --git a/Sources/Core/Buffer/Buffer.swift b/Sources/Core/Buffer/Buffer.swift
index 3d671097..69afb87a 100644
--- a/Sources/Core/Buffer/Buffer.swift
+++ b/Sources/Core/Buffer/Buffer.swift
@@ -99,7 +99,7 @@ extension Collection where Iterator.Element == UInt8 {
         var string = ""
         
         for byte in self {
-            if byte <= 9 {
+            if byte < 0x10 {
                 string += "0"
             }