diff --git a/servo/components/script/dom/document.rs b/servo/components/script/dom/document.rs
index 62fdfbeb1092..dad3cf7c96a4 100644
--- a/servo/components/script/dom/document.rs
+++ b/servo/components/script/dom/document.rs
@@ -1378,6 +1378,21 @@ impl<'a> DocumentMethods for JSRef<'a, Document> {
         HTMLCollection::children(window.r(), NodeCast::from_ref(self))
     }
 
+    // https://dom.spec.whatwg.org/#dom-parentnode-firstelementchild
+    fn GetFirstElementChild(self) -> Option<Temporary<Element>> {
+        NodeCast::from_ref(self).child_elements().next()
+    }
+
+    // https://dom.spec.whatwg.org/#dom-parentnode-lastelementchild
+    fn GetLastElementChild(self) -> Option<Temporary<Element>> {
+        NodeCast::from_ref(self).rev_children().filter_map(ElementCast::to_temporary).next()
+    }
+
+    // https://dom.spec.whatwg.org/#dom-parentnode-childelementcount
+    fn ChildElementCount(self) -> u32 {
+        NodeCast::from_ref(self).child_elements().count() as u32
+    }
+
     // http://dom.spec.whatwg.org/#dom-parentnode-queryselector
     fn QuerySelector(self, selectors: DOMString) -> Fallible<Option<Temporary<Element>>> {
         let root: JSRef<Node> = NodeCast::from_ref(self);
diff --git a/servo/components/script/dom/documentfragment.rs b/servo/components/script/dom/documentfragment.rs
index f8e76103d7df..2a61aa98460e 100644
--- a/servo/components/script/dom/documentfragment.rs
+++ b/servo/components/script/dom/documentfragment.rs
@@ -5,7 +5,8 @@
 use dom::bindings::codegen::Bindings::DocumentFragmentBinding;
 use dom::bindings::codegen::Bindings::DocumentFragmentBinding::DocumentFragmentMethods;
 use dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
-use dom::bindings::codegen::InheritTypes::{DocumentFragmentDerived, NodeCast};
+use dom::bindings::codegen::InheritTypes::DocumentFragmentDerived;
+use dom::bindings::codegen::InheritTypes::{ElementCast, NodeCast};
 use dom::bindings::js::{JSRef, Temporary};
 use dom::bindings::error::Fallible;
 use dom::bindings::global::GlobalRef;
@@ -56,6 +57,21 @@ impl<'a> DocumentFragmentMethods for JSRef<'a, DocumentFragment> {
         HTMLCollection::children(window.r(), NodeCast::from_ref(self))
     }
 
+    // https://dom.spec.whatwg.org/#dom-parentnode-firstelementchild
+    fn GetFirstElementChild(self) -> Option<Temporary<Element>> {
+        NodeCast::from_ref(self).child_elements().next()
+    }
+
+    // https://dom.spec.whatwg.org/#dom-parentnode-lastelementchild
+    fn GetLastElementChild(self) -> Option<Temporary<Element>> {
+        NodeCast::from_ref(self).rev_children().filter_map(ElementCast::to_temporary).next()
+    }
+
+    // https://dom.spec.whatwg.org/#dom-parentnode-childelementcount
+    fn ChildElementCount(self) -> u32 {
+        NodeCast::from_ref(self).child_elements().count() as u32
+    }
+
     // http://dom.spec.whatwg.org/#dom-parentnode-queryselector
     fn QuerySelector(self, selectors: DOMString) -> Fallible<Option<Temporary<Element>>> {
         let root: JSRef<Node> = NodeCast::from_ref(self);
diff --git a/servo/components/script/dom/element.rs b/servo/components/script/dom/element.rs
index c3bf678a48d0..e0e5534c79e8 100644
--- a/servo/components/script/dom/element.rs
+++ b/servo/components/script/dom/element.rs
@@ -1223,6 +1223,21 @@ impl<'a> ElementMethods for JSRef<'a, Element> {
         HTMLCollection::children(window.r(), NodeCast::from_ref(self))
     }
 
+    // https://dom.spec.whatwg.org/#dom-parentnode-firstelementchild
+    fn GetFirstElementChild(self) -> Option<Temporary<Element>> {
+        NodeCast::from_ref(self).child_elements().next()
+    }
+
+    // https://dom.spec.whatwg.org/#dom-parentnode-lastelementchild
+    fn GetLastElementChild(self) -> Option<Temporary<Element>> {
+        NodeCast::from_ref(self).rev_children().filter_map(ElementCast::to_temporary).next()
+    }
+
+    // https://dom.spec.whatwg.org/#dom-parentnode-childelementcount
+    fn ChildElementCount(self) -> u32 {
+        NodeCast::from_ref(self).child_elements().count() as u32
+    }
+
     // http://dom.spec.whatwg.org/#dom-parentnode-queryselector
     fn QuerySelector(self, selectors: DOMString) -> Fallible<Option<Temporary<Element>>> {
         let root: JSRef<Node> = NodeCast::from_ref(self);
diff --git a/servo/components/script/dom/webidls/ParentNode.webidl b/servo/components/script/dom/webidls/ParentNode.webidl
index daa4339611f2..9df1143f6257 100644
--- a/servo/components/script/dom/webidls/ParentNode.webidl
+++ b/servo/components/script/dom/webidls/ParentNode.webidl
@@ -11,14 +11,13 @@
 interface ParentNode {
   [Constant]
   readonly attribute HTMLCollection children;
-  /*
   [Pure]
   readonly attribute Element? firstElementChild;
   [Pure]
   readonly attribute Element? lastElementChild;
   [Pure]
   readonly attribute unsigned long childElementCount;
-  */
+
   // Not implemented yet
   // void prepend((Node or DOMString)... nodes);
   // void append((Node or DOMString)... nodes);