--- a/servo/components/style/dom.rs
+++ b/servo/components/style/dom.rs
@@ -117,16 +117,17 @@ pub struct DomDescendants<N> {
 }
 
 impl<N> Iterator for DomDescendants<N>
 where
     N: TNode
 {
     type Item = N;
 
+    #[inline]
     fn next(&mut self) -> Option<N> {
         let prev = match self.previous.take() {
             None => return None,
             Some(n) => n,
         };
 
         self.previous = prev.next_in_preorder(Some(self.scope));
         self.previous
@@ -200,16 +201,17 @@ pub trait TNode : Sized + Copy + Clone +
         DomDescendants {
             previous: Some(*self),
             scope: *self,
         }
     }
 
     /// Returns the next children in pre-order, optionally scoped to a subtree
     /// root.
+    #[inline]
     fn next_in_preorder(&self, scoped_to: Option<Self>) -> Option<Self> {
         if let Some(c) = self.first_child() {
             return Some(c);
         }
 
         if Some(*self) == scoped_to {
             return None;
         }