diff --git a/components/script/dom/htmldialogelement.rs b/components/script/dom/htmldialogelement.rs
index d6e2a724461..febfbc38f81 100644
--- a/components/script/dom/htmldialogelement.rs
+++ b/components/script/dom/htmldialogelement.rs
@@ -3,18 +3,25 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use dom::bindings::codegen::Bindings::HTMLDialogElementBinding;
+use dom::bindings::codegen::Bindings::HTMLDialogElementBinding::HTMLDialogElementMethods;
 use dom::bindings::codegen::InheritTypes::HTMLDialogElementDerived;
+use dom::bindings::cell::DOMRefCell;
 use dom::bindings::js::{JSRef, Temporary};
 use dom::document::Document;
 use dom::element::ElementTypeId;
 use dom::eventtarget::{EventTarget, EventTargetTypeId};
 use dom::htmlelement::{HTMLElement, HTMLElementTypeId};
 use dom::node::{Node, NodeTypeId};
+
 use util::str::DOMString;
+use string_cache::Atom;
+
+use std::borrow::ToOwned;
 
 #[dom_struct]
 pub struct HTMLDialogElement {
     htmlelement: HTMLElement,
+    return_value: DOMRefCell<DOMString>,
 }
 
 impl HTMLDialogElementDerived for EventTarget {
@@ -26,7 +33,8 @@ impl HTMLDialogElementDerived for EventTarget {
 impl HTMLDialogElement {
     fn new_inherited(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>) -> HTMLDialogElement {
         HTMLDialogElement {
-            htmlelement: HTMLElement::new_inherited(HTMLElementTypeId::HTMLDialogElement, localName, prefix, document)
+            htmlelement: HTMLElement::new_inherited(HTMLElementTypeId::HTMLDialogElement, localName, prefix, document),
+            return_value: DOMRefCell::new("".to_owned()),
         }
     }
 
@@ -37,3 +45,21 @@ impl HTMLDialogElement {
     }
 }
 
+impl<'a> HTMLDialogElementMethods for JSRef<'a, HTMLDialogElement> {
+    // https://html.spec.whatwg.org/multipage/#dom-dialog-open
+    make_bool_getter!(Open);
+
+    // https://html.spec.whatwg.org/multipage/#dom-dialog-open
+    make_bool_setter!(SetOpen, "open");
+
+    // https://html.spec.whatwg.org/multipage/#dom-dialog-returnvalue
+    fn ReturnValue(self) -> DOMString {
+        let return_value = self.return_value.borrow();
+        return_value.clone()
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-dialog-returnvalue
+    fn SetReturnValue(self, return_value: DOMString) {
+        *self.return_value.borrow_mut() = return_value;
+    }
+}
diff --git a/components/script/dom/webidls/HTMLDialogElement.webidl b/components/script/dom/webidls/HTMLDialogElement.webidl
index 659096994e7..aa78cb38aea 100644
--- a/components/script/dom/webidls/HTMLDialogElement.webidl
+++ b/components/script/dom/webidls/HTMLDialogElement.webidl
@@ -5,8 +5,8 @@
 
 // https://www.whatwg.org/html/#htmldialogelement
 interface HTMLDialogElement : HTMLElement {
-  //attribute boolean open;
-  //attribute DOMString returnValue;
+  attribute boolean open;
+  attribute DOMString returnValue;
   //void show(optional (MouseEvent or Element) anchor);
   //void showModal(optional (MouseEvent or Element) anchor);
   //void close(optional DOMString returnValue);
diff --git a/tests/wpt/metadata/html/dom/interfaces.html.ini b/tests/wpt/metadata/html/dom/interfaces.html.ini
index efbe6e1a5b8..b0048beb2f8 100644
--- a/tests/wpt/metadata/html/dom/interfaces.html.ini
+++ b/tests/wpt/metadata/html/dom/interfaces.html.ini
@@ -6678,12 +6678,6 @@
   [HTMLDialogElement interface object length]
     expected: FAIL
 
-  [HTMLDialogElement interface: attribute open]
-    expected: FAIL
-
-  [HTMLDialogElement interface: attribute returnValue]
-    expected: FAIL
-
   [HTMLDialogElement interface: operation show([object Object\],[object Object\])]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/html/dom/reflection-misc.html.ini b/tests/wpt/metadata/html/dom/reflection-misc.html.ini
index c3fcda41468..831c5f16c10 100644
--- a/tests/wpt/metadata/html/dom/reflection-misc.html.ini
+++ b/tests/wpt/metadata/html/dom/reflection-misc.html.ini
@@ -12834,114 +12834,6 @@
   [dialog.tabIndex: IDL set to -2147483648 followed by getAttribute()]
     expected: FAIL
 
-  [dialog.open: typeof IDL attribute]
-    expected: FAIL
-
-  [dialog.open: IDL get with DOM attribute unset]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to "" followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to " foo " followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to undefined followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to null followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to 7 followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to 1.5 followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to true followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to false followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to object "[object Object\]" followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to NaN followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to Infinity followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to -Infinity followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to "\\0" followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to object "test-toString" followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to object "test-valueOf" followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: setAttribute() to "open" followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: IDL set to "" followed by hasAttribute()]
-    expected: FAIL
-
-  [dialog.open: IDL set to "" followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: IDL set to " foo " followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: IDL set to undefined followed by hasAttribute()]
-    expected: FAIL
-
-  [dialog.open: IDL set to undefined followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: IDL set to null followed by hasAttribute()]
-    expected: FAIL
-
-  [dialog.open: IDL set to null followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: IDL set to 7 followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: IDL set to 1.5 followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: IDL set to false followed by hasAttribute()]
-    expected: FAIL
-
-  [dialog.open: IDL set to object "[object Object\]" followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: IDL set to NaN followed by hasAttribute()]
-    expected: FAIL
-
-  [dialog.open: IDL set to NaN followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: IDL set to Infinity followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: IDL set to -Infinity followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: IDL set to "\\0" followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: IDL set to object "test-toString" followed by IDL get]
-    expected: FAIL
-
-  [dialog.open: IDL set to object "test-valueOf" followed by IDL get]
-    expected: FAIL
-
   [dialog.itemScope: typeof IDL attribute]
     expected: FAIL