diff --git a/src/unix/notbsd/linux/other/mod.rs b/src/unix/notbsd/linux/other/mod.rs
index 96bfa126..740dd8da 100644
--- a/src/unix/notbsd/linux/other/mod.rs
+++ b/src/unix/notbsd/linux/other/mod.rs
@@ -611,7 +611,7 @@ extern {
                                          val: ::c_int) -> ::c_int;
     pub fn sched_getcpu() -> ::c_int;
     pub fn mallinfo() -> ::mallinfo;
-    pub fn malloc_usable_size(ptr: *const ::c_void) -> ::size_t;
+    pub fn malloc_usable_size(ptr: *mut ::c_void) -> ::size_t;
     pub fn memfd_create(name: *const c_char, flags: ::c_uint) -> ::c_int;
     pub fn getauxval(type_: ::c_ulong) -> ::c_ulong;
 }