diff --git a/apps/macos/VODManager/Sources/VODManager/Services/VODSignature.swift b/apps/macos/VODManager/Sources/VODManager/Services/VODSignature.swift
index 5692538..b2436b8 100644
--- a/apps/macos/VODManager/Sources/VODManager/Services/VODSignature.swift
+++ b/apps/macos/VODManager/Sources/VODManager/Services/VODSignature.swift
@@ -26,6 +26,8 @@ struct VODSignature {
 
         let stringToSign = "\(method)&%2F&\(percentEncode(canonicalQuery))"
 
+        print("[VODSignature] stringToSign: \(stringToSign)")
+
         guard let keyData = "\(accessKeySecret)&".data(using: .utf8) else {
             throw VODSignatureError.invalidKey
         }
@@ -40,7 +42,15 @@ struct VODSignature {
     }
 
     private static func percentEncode(_ value: String) -> String {
-        let allowed = CharacterSet(charactersIn: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_.~")
-        return value.addingPercentEncoding(withAllowedCharacters: allowed) ?? value
+        let allowed = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_.~"
+        var result = ""
+        for char in value.utf8 {
+            if allowed.utf8.contains(char) {
+                result.append(Character(UnicodeScalar(char)))
+            } else {
+                result.append(String(format: "%%%02X", char))
+            }
+        }
+        return result
     }
 }