diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 977bff505dc..3f1bf1c450a 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -377,6 +377,8 @@ pub struct Document {
     delayed_tasks: DomRefCell<Vec<Box<dyn TaskBox>>>,
     /// https://html.spec.whatwg.org/multipage/#completely-loaded
     completely_loaded: Cell<bool>,
+    /// List of shadow roots bound to the document tree.
+    shadow_roots: DomRefCell<Vec<Dom<ShadowRoot>>>,
 }
 
 #[derive(JSTraceable, MallocSizeOf)]
@@ -2680,6 +2682,7 @@ impl Document {
             completely_loaded: Cell::new(false),
             script_and_layout_blockers: Cell::new(0),
             delayed_tasks: Default::default(),
+            shadow_roots: DomRefCell::new(Vec::new()),
         }
     }
 
@@ -3132,6 +3135,20 @@ impl Document {
             }
         }
     }
+
+    pub fn register_shadow_root(&self, shadow_root: &ShadowRoot) {
+        self.shadow_roots
+            .borrow_mut()
+            .push(Dom::from_ref(shadow_root));
+    }
+
+    pub fn unregister_shadow_root(&self, shadow_root: &ShadowRoot) {
+        let mut shadow_roots = self.shadow_roots.borrow_mut();
+        let position = shadow_roots.iter().position(|sr| **sr == *shadow_root);
+        if let Some(index) = position {
+            shadow_roots.remove(index);
+        }
+    }
 }
 
 impl Element {
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index 4b24ab84a90..7a69d4c781f 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -486,9 +486,13 @@ impl Element {
         }
 
         // Steps 4, 5 and 6.
-        Ok(self
+        let shadow_root = self
             .shadow_root
-            .or_init(|| ShadowRoot::new(self, &*self.node.owner_doc())))
+            .or_init(|| ShadowRoot::new(self, &*self.node.owner_doc()));
+
+        self.node.owner_doc().register_shadow_root(&*shadow_root);
+
+        Ok(shadow_root)
     }
 }
 
@@ -2787,8 +2791,9 @@ impl VirtualMethods for Element {
             return;
         }
 
-        if self.is_shadow_host() {
-            let shadow_root = self.shadow_root.get().unwrap();
+        let doc = document_from_node(self);
+
+        if let Some(shadow_root) = self.upcast::<Node>().owner_shadow_root() {
             let shadow_root = shadow_root.upcast::<Node>();
             shadow_root.set_flag(NodeFlags::IS_CONNECTED, tree_connected);
             for node in shadow_root.children() {
@@ -2797,7 +2802,6 @@ impl VirtualMethods for Element {
             }
         }
 
-        let doc = document_from_node(self);
         if let Some(ref value) = *self.id_attribute.borrow() {
             doc.register_named_element(self, value.clone());
         }
@@ -2816,8 +2820,12 @@ impl VirtualMethods for Element {
             return;
         }
 
+        let doc = document_from_node(self);
+
         if self.is_shadow_host() {
             let shadow_root = self.shadow_root.get().unwrap();
+            doc.unregister_shadow_root(&shadow_root);
+            let shadow_root = shadow_root.upcast::<Node>();
             let shadow_root = shadow_root.upcast::<Node>();
             shadow_root.set_flag(NodeFlags::IS_CONNECTED, false);
             for node in shadow_root.children() {
@@ -2826,7 +2834,6 @@ impl VirtualMethods for Element {
             }
         }
 
-        let doc = document_from_node(self);
         let fullscreen = doc.GetFullscreenElement();
         if fullscreen.deref() == Some(self) {
             doc.exit_fullscreen();