diff --git a/testing/mochitest/b2g-debug.json b/testing/mochitest/b2g-debug.json
index a4f25dad2d4..cd0e5606393 100644
--- a/testing/mochitest/b2g-debug.json
+++ b/testing/mochitest/b2g-debug.json
@@ -166,6 +166,8 @@
     "content/events/test/test_bug508479.html":"drag event, also fails on Android",
     "content/events/test/test_dragstart.html":"drag event, also fails on Android",
 
+    "content/events/test/test_bug864040.html":"failing when the test gets moved around, and on debug",
+
     "content/html/content/test/forms/test_input_file_picker.html":"5 failures out of 139 and timing out, bug 901581",
     "content/html/content/test/forms/test_validation.html":"374 total, bug 901848, no keygen support",
 
diff --git a/testing/mochitest/b2g-desktop.json b/testing/mochitest/b2g-desktop.json
index f3c9ca7111a..197d67d1cd6 100644
--- a/testing/mochitest/b2g-desktop.json
+++ b/testing/mochitest/b2g-desktop.json
@@ -167,6 +167,8 @@
     "content/events/test/test_bug508479.html":"drag event, also fails on Android",
     "content/events/test/test_dragstart.html":"drag event, also fails on Android",
 
+    "content/events/test/test_bug864040.html":"failing when the test gets moved around, and on debug",
+
     "content/html/content/test/forms/test_input_file_picker.html":"5 failures out of 139 and timing out, bug 901581",
     "content/html/content/test/forms/test_validation.html":"374 total, bug 901848, no keygen support",
 
diff --git a/testing/mochitest/b2g.json b/testing/mochitest/b2g.json
index 3ebd6a20bd4..cffa60dd1ee 100644
--- a/testing/mochitest/b2g.json
+++ b/testing/mochitest/b2g.json
@@ -167,6 +167,8 @@
     "content/events/test/test_bug508479.html":"drag event, also fails on Android",
     "content/events/test/test_dragstart.html":"drag event, also fails on Android",
 
+    "content/events/test/test_bug864040.html":"failing when the test gets moved around, and on debug",
+
     "content/html/content/test/forms/test_input_file_picker.html":"5 failures out of 139 and timing out, bug 901581",
     "content/html/content/test/forms/test_validation.html":"374 total, bug 901848, no keygen support",