diff --git a/src/redox.rs b/src/redox.rs
index 7a05a3957b181..eb1ce0d9a4674 100644
--- a/src/redox.rs
+++ b/src/redox.rs
@@ -47,3 +47,7 @@ s! {
         pub sin6_scope_id: u32,
     }
 }
+
+extern {
+    pub fn memalign(align: ::size_t, size: ::size_t) -> *mut ::c_void;
+}