diff --git a/testing/web-platform/meta/media-source/mediasource-duration.html.ini b/testing/web-platform/meta/media-source/mediasource-duration.html.ini
index 9a790175eab1..fd7075ab0b6d 100644
--- a/testing/web-platform/meta/media-source/mediasource-duration.html.ini
+++ b/testing/web-platform/meta/media-source/mediasource-duration.html.ini
@@ -1,17 +1,4 @@
 [mediasource-duration.html]
   type: testharness
-  expected: TIMEOUT
-  [Test seek starts on duration truncation below currentTime]
-    disabled: TIMEOUT or FAIL https://bugzilla.mozilla.org/show_bug.cgi?id=1085247
-
-  [Test appendBuffer completes previous seek to truncated duration]
-    disabled: TIMEOUT or FAIL https://bugzilla.mozilla.org/show_bug.cgi?id=1085247
-
-  [Test endOfStream completes previous seek to truncated duration]
-    disabled: TIMEOUT or FAIL https://bugzilla.mozilla.org/show_bug.cgi?id=1085247
-
-  [Test setting same duration multiple times does not fire duplicate durationchange]
-    expected:
-      if os == "win" and version != "5.1.2600": TIMEOUT
-      FAIL
+  disabled: TIMEOUT or FAIL https://bugzilla.mozilla.org/show_bug.cgi?id=1085247
 
diff --git a/testing/web-platform/meta/media-source/mediasource-redundant-seek.html.ini b/testing/web-platform/meta/media-source/mediasource-redundant-seek.html.ini
index c9fa66c425a4..bd3e9b123e14 100644
--- a/testing/web-platform/meta/media-source/mediasource-redundant-seek.html.ini
+++ b/testing/web-platform/meta/media-source/mediasource-redundant-seek.html.ini
@@ -1,6 +1,4 @@
 [mediasource-redundant-seek.html]
   type: testharness
-  expected: TIMEOUT
-  [Test redundant fully prebuffered seek]
-    expected: TIMEOUT
+  disabled: TIMEOUT or FAIL