diff --git a/testing/web-platform/meta/MANIFEST.json b/testing/web-platform/meta/MANIFEST.json
index 5e06210e0313..67e94b11f686 100644
--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -13807,6 +13807,12 @@
      {}
     ]
    ],
+   "pointerlock/mouse_buttons_back_forward-manual.html": [
+    [
+     "/pointerlock/mouse_buttons_back_forward-manual.html",
+     {}
+    ]
+   ],
    "pointerlock/movementX_Y_basic-manual.html": [
     [
      "/pointerlock/movementX_Y_basic-manual.html",
@@ -604152,6 +604158,10 @@
    "0838cc19db0518e115adbe07f01b195dc8b5db6f",
    "testharness"
   ],
+  "pointerlock/mouse_buttons_back_forward-manual.html": [
+   "0801af4a1f9fc2664a53d7a12d4cbec0092cd1de",
+   "manual"
+  ],
   "pointerlock/movementX_Y_basic-manual.html": [
    "45eea8be5393873e6c02331b4aff6f4622be692f",
    "manual"
diff --git a/testing/web-platform/tests/pointerlock/mouse_buttons_back_forward-manual.html b/testing/web-platform/tests/pointerlock/mouse_buttons_back_forward-manual.html
new file mode 100644
index 000000000000..06e0a5daee1c
--- /dev/null
+++ b/testing/web-platform/tests/pointerlock/mouse_buttons_back_forward-manual.html
@@ -0,0 +1,41 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="utf-8" />
+        <title>Mouse Button Back/Forward</title>
+        <link rel="author" title="Google" href="http://www.google.com/" />
+        <script src="/resources/testharness.js"></script>
+        <script src="/resources/testharnessreport.js"></script>
+        <script>
+            var testMouseUp = async_test('Tests that when pointer is locked, the mouseup is preventable.');
+            var received_back = false;
+            var received_forward = false;
+            window.addEventListener('mouseup', function(e) {
+              if (e.button == 0) {
+                document.body.requestPointerLock();
+              } else if (e.button == 3) {
+                received_back = true;
+                e.preventDefault();
+              } else if (e.button == 4) {
+                received_forward = true;
+                e.preventDefault();
+              }
+              if (document.pointerLockElement && received_back && received_forward) {
+                testMouseUp.done();
+                document.exitPointerLock();
+              }
+            });
+
+        </script>
+
+    </head>
+    <body id="target">
+        <h4>Test Description: Tests that the mouseup event is prevented.
+            <ol>
+                <li>Click the left mouse button to lock pointer</li>
+                <li>Click the back mouse button</li>
+                <li>Click the back mouse forward</li>
+            </ol>
+        </h4>
+    </body>
+</html>
