3 files changed, 27 insertions, 8 deletions
diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 2a7466dc2eb..c142945d131 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -2551,8 +2551,12 @@ impl DocumentMethods for Document {
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-document-defaultview
-    fn DefaultView(&self) -> Root<Window> {
-        Root::from_ref(&*self.window)
+    fn GetDefaultView(&self) -> Option<Root<Window>> {
+        if self.browsing_context.is_none() {
+            None
+        } else {
+            Some(Root::from_ref(&*self.window))
+        }
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-document-cookie
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index 34791c3417c..e2398a14139 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -1297,7 +1297,10 @@ impl Element {
         }
 
         // Step 5
-        let win = doc.DefaultView();
+        let win = match doc.GetDefaultView() {
+            None => return,
+            Some(win) => win,
+        };
 
         // Step 7
         if *self.root_element() == *self {
@@ -1635,7 +1638,10 @@ impl ElementMethods for Element {
         }
 
         // Step 3
-        let win = doc.DefaultView();
+        let win = match doc.GetDefaultView() {
+            None => return 0.0,
+            Some(win) => win,
+        };
 
         // Step 5
         if *self.root_element() == *self {
@@ -1683,7 +1689,10 @@ impl ElementMethods for Element {
         }
 
         // Step 5
-        let win = doc.DefaultView();
+        let win = match doc.GetDefaultView() {
+            None => return,
+            Some(win) => win,
+        };
 
         // Step 7
         if *self.root_element() == *self {
@@ -1721,7 +1730,10 @@ impl ElementMethods for Element {
         }
 
         // Step 3
-        let win = doc.DefaultView();
+        let win = match doc.GetDefaultView() {
+            None => return 0.0,
+            Some(win) => win,
+        };
 
         // Step 5
         if *self.root_element() == *self {
@@ -1769,7 +1781,10 @@ impl ElementMethods for Element {
         }
 
         // Step 5
-        let win = doc.DefaultView();
+        let win = match doc.GetDefaultView() {
+            None => return,
+            Some(win) => win,
+        };
 
         // Step 7
         if *self.root_element() == *self {
diff --git a/components/script/dom/webidls/Document.webidl b/components/script/dom/webidls/Document.webidl
index 0e5c7b661a6..6b365378c92 100644
--- a/components/script/dom/webidls/Document.webidl
+++ b/components/script/dom/webidls/Document.webidl
@@ -118,7 +118,7 @@ partial /*sealed*/ interface Document {
   // void writeln(DOMString... text);
 
   // user interaction
-  readonly attribute Window/*Proxy?*/ defaultView;
+  readonly attribute Window?/*Proxy?*/ defaultView;
   readonly attribute Element? activeElement;
   boolean hasFocus();
   // attribute DOMString designMode;