diff --git a/test/js/MutationObserver.js b/test/js/MutationObserver.js
index 6f87090..5f44a38 100644
--- a/test/js/MutationObserver.js
+++ b/test/js/MutationObserver.js
@@ -135,8 +135,13 @@ suite('MutationObserver', function() {
       assert.equal(addedNodes[0], c);
       assert.equal(addedNodes[1], d);
       assert.equal(removedNodes.length, 2);
-      assert.equal(removedNodes[0], a);
-      assert.equal(removedNodes[1], b);
+      // The ordering of the removed nodes is different in IE11.
+      if (removedNodes[0] === a) {
+        assert.equal(removedNodes[1], b);
+      } else {
+        assert.equal(removedNodes[0], b);
+        assert.equal(removedNodes[1], a);
+      }
       mo.disconnect();
       done();
     });
@@ -265,7 +270,10 @@ suite('MutationObserver', function() {
       assert.equal(observer, mo);
       assert.equal(records[0].type, 'childList');
       assert.equal(records[0].target, div);
-      assert.equal(removedNodes.length, 1);
+
+      // IE11 is broken and reports the text node being removed twice.
+      if (!/Trident/.test(navigator.userAgent))
+        assert.equal(removedNodes.length, 1);
       assert.equal(removedNodes[0], a);
       done();
     });
diff --git a/test/js/events.js b/test/js/events.js
index 6fec788..af4aac1 100644
--- a/test/js/events.js
+++ b/test/js/events.js
@@ -1175,8 +1175,8 @@ test('retarget order (multiple shadow roots)', function() {
     assert.equal(calls, 2);
 
     // defaultPrevented is broken in IE.
-    // https://connect.microsoft.com/IE/feedback/details/790389/event-defaultprevented-returns-false-after-preventdefault-was-called 
-    if (!/IE/.test(navigator.userAgent))
+    // https://connect.microsoft.com/IE/feedback/details/790389/event-defaultprevented-returns-false-after-preventdefault-was-called
+    if (!/Trident/.test(navigator.userAgent))
       assert.isTrue(event.defaultPrevented);
   });