diff --git a/mirai-core/src/main/java/net/mamoe/mirai/network/packet/ClientPacket.kt b/mirai-core/src/main/java/net/mamoe/mirai/network/packet/ClientPacket.kt
index e1d671231..c94621597 100644
--- a/mirai-core/src/main/java/net/mamoe/mirai/network/packet/ClientPacket.kt
+++ b/mirai-core/src/main/java/net/mamoe/mirai/network/packet/ClientPacket.kt
@@ -104,7 +104,7 @@ fun DataOutputStream.writeHex(hex: String) {
         if (s.isEmpty()) {
             continue
         }
-        this.writeByte(s.toUByte(16).toByte().toInt())
+        this.writeByte(s.toUByte(16).toInt())
     }
 }
 
diff --git a/mirai-core/src/main/java/net/mamoe/mirai/network/packet/image/ClientGetGroupImageIDPacket.kt b/mirai-core/src/main/java/net/mamoe/mirai/network/packet/image/ClientGetGroupImageIDPacket.kt
index f3e09c45d..9834ce63c 100644
--- a/mirai-core/src/main/java/net/mamoe/mirai/network/packet/image/ClientGetGroupImageIDPacket.kt
+++ b/mirai-core/src/main/java/net/mamoe/mirai/network/packet/image/ClientGetGroupImageIDPacket.kt
@@ -70,8 +70,9 @@ class ClientGetGroupImageIDPacket(
 
             it.writeHex("60 04")
 
-            it.writeHex("6A 05")
-            it.writeHex("32 36 36 35 36 05")
+            it.writeHex("6A")
+            it.writeHex("05")
+            it.writeHex("32 36 36 35 36 05")//6?
 
             it.writeHex("70 00")