diff --git a/xposed/src/main/java/moe/fuqiuluo/proto/Proto.kt b/xposed/src/main/java/moe/fuqiuluo/proto/Proto.kt
index f5cd539e..acda8731 100644
--- a/xposed/src/main/java/moe/fuqiuluo/proto/Proto.kt
+++ b/xposed/src/main/java/moe/fuqiuluo/proto/Proto.kt
@@ -50,7 +50,7 @@ val ProtoValue.asLong: Long
     get() = (this as ProtoNumber).value.toLong()
 
 val ProtoValue.asULong: Long
-    get() = (this as ProtoNumber).value.toLong() and 0xFFFFFFFFL
+    get() = (this as ProtoNumber).value.toLong() and Long.MAX_VALUE
 
 val ProtoValue.asMap: ProtoMap
     get() = (this as ProtoMap)