diff --git a/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-021.htm.ini b/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-021.htm.ini
index 60311d755b8..dcedfa1e69b 100644
--- a/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-021.htm.ini
+++ b/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-021.htm.ini
@@ -1,4 +1,5 @@
 [absolute-replaced-height-021.htm]
   type: reftest
+  disabled: unstable
   expected:
     if (os == "mac") and (version == "OS X 10.8.5"): FAIL
diff --git a/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-028.htm.ini b/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-028.htm.ini
new file mode 100644
index 00000000000..f0774cb81ff
--- /dev/null
+++ b/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-028.htm.ini
@@ -0,0 +1,3 @@
+[absolute-replaced-height-028.htm]
+  type: reftest
+  disabled: unstable
diff --git a/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-035.htm.ini b/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-035.htm.ini
new file mode 100644
index 00000000000..831d1b817a0
--- /dev/null
+++ b/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-035.htm.ini
@@ -0,0 +1,3 @@
+[absolute-replaced-height-035.htm]
+  type: reftest
+  disabled: unstable
diff --git a/tests/wpt/metadata-css/css21_dev/html4/background-root-103.htm b/tests/wpt/metadata-css/css21_dev/html4/background-root-103.htm
new file mode 100644
index 00000000000..6bd313acbfe
--- /dev/null
+++ b/tests/wpt/metadata-css/css21_dev/html4/background-root-103.htm
@@ -0,0 +1,3 @@
+[background-root-103.htm]
+  type: reftest
+  disabled: unstable