diff --git a/src/advance/unsafe/superpowers.md b/src/advance/unsafe/superpowers.md
index b56b905e..a96e69ab 100644
--- a/src/advance/unsafe/superpowers.md
+++ b/src/advance/unsafe/superpowers.md
@@ -113,7 +113,7 @@ let a: Box<i32> = Box::new(10);
 // 需要先解引用a
 let b: *const i32 = &*a;
 // 使用 into_raw 来创建
-let c: *const i32 = Box::into_raw(a);
+let c: *mut i32 = Box::into_raw(a);
 ```
 
 #### 小结