diff --git a/dom/base/DocumentOrShadowRoot.cpp b/dom/base/DocumentOrShadowRoot.cpp
index f20b9dc4f74e..f992da00f5b7 100644
--- a/dom/base/DocumentOrShadowRoot.cpp
+++ b/dom/base/DocumentOrShadowRoot.cpp
@@ -5,6 +5,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "DocumentOrShadowRoot.h"
+#include "mozilla/EventStateManager.h"
 #include "mozilla/dom/StyleSheetList.h"
 #include "nsDocument.h"
 #include "nsFocusManager.h"
@@ -130,5 +131,20 @@ DocumentOrShadowRoot::GetRetargetedFocusedElement()
   return nullptr;
 }
 
+Element*
+DocumentOrShadowRoot::GetPointerLockElement()
+{
+  nsCOMPtr<Element> pointerLockedElement =
+    do_QueryReferent(EventStateManager::sPointerLockedElement);
+  if (!pointerLockedElement) {
+    return nullptr;
+  }
+
+  nsIContent* retargetedPointerLockedElement = Retarget(pointerLockedElement);
+  return
+    retargetedPointerLockedElement && retargetedPointerLockedElement->IsElement() ?
+      retargetedPointerLockedElement->AsElement() : nullptr;
+}
+
 }
 }
diff --git a/dom/base/DocumentOrShadowRoot.h b/dom/base/DocumentOrShadowRoot.h
index f5fd7d0eb4de..f6c783085b44 100644
--- a/dom/base/DocumentOrShadowRoot.h
+++ b/dom/base/DocumentOrShadowRoot.h
@@ -113,6 +113,7 @@ public:
 
   ~DocumentOrShadowRoot() = default;
 
+  Element* GetPointerLockElement();
 protected:
   nsIContent* Retarget(nsIContent* aContent) const;
 
diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index 18e0a096c1e5..131fc69d0b79 100644
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -11640,7 +11640,7 @@ GetPointerLockError(Element* aElement, Element* aCurrentLock,
     return "PointerLockDeniedInUse";
   }
 
-  if (!aElement->IsInUncomposedDoc()) {
+  if (!aElement->IsInComposedDoc()) {
     return "PointerLockDeniedNotInDocument";
   }
 
@@ -11691,11 +11691,11 @@ ChangePointerLockedElement(Element* aElement, nsIDocument* aDocument,
   MOZ_ASSERT(aDocument);
   MOZ_ASSERT(aElement != aPointerLockedElement);
   if (aPointerLockedElement) {
-    MOZ_ASSERT(aPointerLockedElement->GetUncomposedDoc() == aDocument);
+    MOZ_ASSERT(aPointerLockedElement->GetComposedDoc() == aDocument);
     aPointerLockedElement->ClearPointerLock();
   }
   if (aElement) {
-    MOZ_ASSERT(aElement->GetUncomposedDoc() == aDocument);
+    MOZ_ASSERT(aElement->GetComposedDoc() == aDocument);
     aElement->SetPointerLock();
     EventStateManager::sPointerLockedElement = do_GetWeakReference(aElement);
     EventStateManager::sPointerLockedDoc = do_GetWeakReference(aDocument);
@@ -11719,9 +11719,9 @@ PointerLockRequest::Run()
   nsCOMPtr<nsIDocument> doc = do_QueryReferent(mDocument);
   nsDocument* d = static_cast<nsDocument*>(doc.get());
   const char* error = nullptr;
-  if (!e || !d || !e->GetUncomposedDoc()) {
+  if (!e || !d || !e->GetComposedDoc()) {
     error = "PointerLockDeniedNotInDocument";
-  } else if (e->GetUncomposedDoc() != d) {
+  } else if (e->GetComposedDoc() != d) {
     error = "PointerLockDeniedMovedDocument";
   }
   if (!error) {
@@ -11872,25 +11872,6 @@ nsIDocument::UnlockPointer(nsIDocument* aDoc)
   nsDocument::UnlockPointer(aDoc);
 }
 
-Element*
-nsIDocument::GetPointerLockElement()
-{
-  nsCOMPtr<Element> pointerLockedElement =
-    do_QueryReferent(EventStateManager::sPointerLockedElement);
-  if (!pointerLockedElement) {
-    return nullptr;
-  }
-
-  // Make sure pointer locked element is in the same document.
-  nsCOMPtr<nsIDocument> pointerLockedDoc =
-    do_QueryReferent(EventStateManager::sPointerLockedDoc);
-  if (pointerLockedDoc != this) {
-    return nullptr;
-  }
-
-  return pointerLockedElement;
-}
-
 void
 nsDocument::UpdateVisibilityState()
 {
diff --git a/dom/base/nsIDocument.h b/dom/base/nsIDocument.h
index 034de076b63c..66ec6974a1ff 100644
--- a/dom/base/nsIDocument.h
+++ b/dom/base/nsIDocument.h
@@ -2932,7 +2932,6 @@ public:
     return !!GetFullscreenElement();
   }
   void ExitFullscreen();
-  Element* GetPointerLockElement();
   void ExitPointerLock()
   {
     UnlockPointer(this);
diff --git a/dom/tests/mochitest/pointerlock/file_pointerlock-api-with-shadow.html b/dom/tests/mochitest/pointerlock/file_pointerlock-api-with-shadow.html
new file mode 100644
index 000000000000..b80a61ed112b
--- /dev/null
+++ b/dom/tests/mochitest/pointerlock/file_pointerlock-api-with-shadow.html
@@ -0,0 +1,110 @@
+<!DOCTYPE HTML>
+<html>
+<!--https://bugzilla.mozilla.org/show_bug.cgi?id=633602-->
+<head>
+  <title>Bug 633602</title>
+  <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js">
+  </script>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js">
+  </script>
+  <script type="application/javascript" src="pointerlock_utils.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+  <a target="_blank"
+    href="https://bugzilla.mozilla.org/show_bug.cgi?id=633602">
+    Mozilla Bug 633602
+  </a>
+  <div id="host"></div>
+  <pre id="test">
+    <script type="text/javascript">
+      /*
+       * Test for Bug 1430303
+       * Make sure DOM API is correct.
+       */
+
+      SimpleTest.waitForExplicitFinish();
+
+      var div,
+        host,
+        hasRequestPointerLock = false,
+        pointerLockChangeEventFired = false,
+        pointerUnlocked = false,
+        pointerLocked = false,
+        hasExitPointerLock = false,
+        pointerLockElement = false,
+        hasMovementX = false,
+        hasMovementY = false;
+        gotContextMenuEvent = false;
+
+      function runTests () {
+        ok(hasRequestPointerLock, "Element should have requestPointerLock.");
+        ok(pointerLockChangeEventFired, "pointerlockchange event should fire.");
+        ok(pointerUnlocked, "Should be able to unlock pointer locked element.");
+        ok(pointerLocked, "Requested element should be able to lock.");
+        ok(hasExitPointerLock, "Document should have exitPointerLock");
+        ok(pointerLockElement, "Document should keep track of correct pointer locked element");
+        ok(hasMovementX, "Mouse Event should have movementX.");
+        ok(hasMovementY, "Mouse Event should have movementY.");
+        ok(!gotContextMenuEvent, "Shouldn't have got a contextmenu event.");
+      }
+
+      function mouseMoveHandler(e) {
+        info("Got mousemove");
+        document.removeEventListener("mousemove", mouseMoveHandler);
+
+        hasMovementX = "movementX" in e;
+        hasMovementY = "movementY" in e;
+
+        hasExitPointerLock = "exitPointerLock" in document;
+        document.exitPointerLock();
+      }
+
+      document.addEventListener("pointerlockchange", function (e) {
+        pointerLockChangeEventFired = true;
+
+        if (document.pointerLockElement) {
+          info("Got pointerlockchange for entering");
+          pointerLocked = true;
+          pointerLockElement = document.pointerLockElement === host;
+          is(host.shadowRoot.firstChild, host.shadowRoot.pointerLockElement,
+             "ShadowRoot's pointerLockElement shouldn't be retargeted.");
+ 
+          window.addEventListener("contextmenu",
+                                  function() { gotContextMenuEvent = true; },
+                                  true);
+          synthesizeMouse(document.body, 4, 4,
+                          { type: "contextmenu", button: 2 },
+                          window);
+
+          document.addEventListener("mousemove", mouseMoveHandler);
+          synthesizeMouseAtCenter(host, {type: "mousemove"}, window);
+        } else {
+          info("Got pointerlockchange for exiting");
+          pointerUnlocked = true;
+          addFullscreenChangeContinuation("exit", function() {
+            info("Got fullscreenchange for exiting");
+            runTests();
+            SimpleTest.finish();
+          });
+          document.exitFullscreen();
+        }
+      });
+
+      function start() {
+        host = document.getElementById("host");
+        var sr = host.attachShadow({mode: "open"});
+        sr.innerHTML = "<div><div>";
+        div = sr.firstChild;
+        info("Requesting fullscreen on parent");
+        addFullscreenChangeContinuation("enter", function() {
+          info("Got fullscreenchange for entering");
+          hasRequestPointerLock = "requestPointerLock" in div;
+          div.requestPointerLock();
+        });
+        host.requestFullscreen();
+      }
+    </script>
+  </pre>
+</body>
+</html>
diff --git a/dom/tests/mochitest/pointerlock/mochitest.ini b/dom/tests/mochitest/pointerlock/mochitest.ini
index f332e4928d82..b5116dc1dae5 100644
--- a/dom/tests/mochitest/pointerlock/mochitest.ini
+++ b/dom/tests/mochitest/pointerlock/mochitest.ini
@@ -9,6 +9,7 @@ tags = fullscreen
 support-files =
   pointerlock_utils.js
   file_pointerlock-api.html
+  file_pointerlock-api-with-shadow.html
   file_pointerlockerror.html
   file_escapeKey.html
   file_withoutDOM.html
diff --git a/dom/tests/mochitest/pointerlock/test_pointerlock-api.html b/dom/tests/mochitest/pointerlock/test_pointerlock-api.html
index 3094c565e711..f7eceab6a27f 100644
--- a/dom/tests/mochitest/pointerlock/test_pointerlock-api.html
+++ b/dom/tests/mochitest/pointerlock/test_pointerlock-api.html
@@ -33,7 +33,8 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=633602
           ["full-screen-api.unprefix.enabled", true],
           ["full-screen-api.allow-trusted-requests-only", false],
           ["full-screen-api.transition-duration.enter", "0 0"],
-          ["full-screen-api.transition-duration.leave", "0 0"]
+          ["full-screen-api.transition-duration.leave", "0 0"],
+          ["dom.webcomponents.shadowdom.enabled", true]
         ]}, nextTest);
 
         // Run the tests which go full-screen in new window, as Mochitests
@@ -49,6 +50,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=633602
           "file_movementXY.html",
           "file_nestedFullScreen.html",
           "file_pointerlock-api.html",
+          "file_pointerlock-api-with-shadow.html",
           "file_pointerlockerror.html",
           "file_pointerLockPref.html",
           "file_removedFromDOM.html",
diff --git a/dom/webidl/Document.webidl b/dom/webidl/Document.webidl
index bb9e0022b1b1..d743404a7e08 100644
--- a/dom/webidl/Document.webidl
+++ b/dom/webidl/Document.webidl
@@ -262,7 +262,6 @@ partial interface Document {
 // https://w3c.github.io/pointerlock/#extensions-to-the-document-interface
 // https://w3c.github.io/pointerlock/#extensions-to-the-documentorshadowroot-mixin
 partial interface Document {
-  readonly attribute Element? pointerLockElement;
   void exitPointerLock();
 
   // Event handlers
diff --git a/dom/webidl/DocumentOrShadowRoot.webidl b/dom/webidl/DocumentOrShadowRoot.webidl
index 16388d1264f8..267f16f23b65 100644
--- a/dom/webidl/DocumentOrShadowRoot.webidl
+++ b/dom/webidl/DocumentOrShadowRoot.webidl
@@ -22,8 +22,7 @@ interface DocumentOrShadowRoot {
   readonly attribute Element? activeElement;
   readonly attribute StyleSheetList styleSheets;
 
-  // Not implemented yet: bug 1430303.
-  // readonly attribute Element? pointerLockElement;
+  readonly attribute Element? pointerLockElement;
   // Not implemented yet: bug 1430305.
   // readonly attribute Element? fullscreenElement;
 };