diff --git a/ports/cef/lib.rs b/ports/cef/lib.rs
index 8d0bd76648f..f92b5adeaf8 100644
--- a/ports/cef/lib.rs
+++ b/ports/cef/lib.rs
@@ -10,7 +10,6 @@
 #![feature(filling_drop)]
 #![feature(iter_arith)]
 #![feature(link_args)]
-#![feature(negate_unsigned)]
 #![feature(plugin)]
 #![feature(str_utf16)]
 #![feature(unicode)]
diff --git a/ports/cef/window.rs b/ports/cef/window.rs
index 0d404268ada..a25b48e3681 100644
--- a/ports/cef/window.rs
+++ b/ports/cef/window.rs
@@ -51,7 +51,7 @@ pub struct Window {
 
 #[cfg(target_os="macos")]
 fn load_gl() {
-    const RTLD_DEFAULT: *mut c_void = (-2) as *mut c_void;
+    const RTLD_DEFAULT: *mut c_void = (-2isize) as usize as *mut c_void;
 
     extern {
         fn dlsym(handle: *mut c_void, symbol: *const c_char) -> *mut c_void;