--- a/servo/components/style/gecko_string_cache/mod.rs
+++ b/servo/components/style/gecko_string_cache/mod.rs
@@ -151,21 +151,18 @@ impl WeakAtom {
         unsafe {
             (*self.as_ptr()).mIsStatic() != 0
         }
     }
 
     /// Returns the length of the atom string.
     #[inline]
     pub fn len(&self) -> u32 {
-        // FIXME(emilio): re-introduce bitfield accessors:
-        //
-        // https://github.com/servo/rust-bindgen/issues/519
         unsafe {
-            (*self.as_ptr())._bitfield_1 & 0x7FFFFFFF
+            (*self.as_ptr()).mLength()
         }
     }
 
     /// Returns whether this atom is the empty string.
     #[inline]
     pub fn is_empty(&self) -> bool {
         self.len() == 0
     }