diff --git a/src/unix/notbsd/android/mod.rs b/src/unix/notbsd/android/mod.rs
index 2dc1e386b872b5bc3fdb05d4b58bbea274f48278..e614427080d73effb15d18d768a6e0986525402d 100644
--- a/src/unix/notbsd/android/mod.rs
+++ b/src/unix/notbsd/android/mod.rs
@@ -1938,7 +1938,7 @@ extern {
     pub fn ioctl(fd: ::c_int, request: ::c_int, ...) -> ::c_int;
     pub fn msync(addr: *mut ::c_void, len: ::size_t,
                  flags: ::c_int) -> ::c_int;
-    pub fn mprotect(addr: *const ::c_void, len: ::size_t, prot: ::c_int)
+    pub fn mprotect(addr: *mut ::c_void, len: ::size_t, prot: ::c_int)
                     -> ::c_int;
     pub fn recvfrom(socket: ::c_int, buf: *mut ::c_void, len: ::size_t,
                     flags: ::c_int, addr: *const ::sockaddr,