diff --git a/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-007.htm.ini b/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-007.htm.ini
index 90bb5745029..e80eb8c84cc 100644
--- a/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-007.htm.ini
+++ b/tests/wpt/metadata-css/css21_dev/html4/absolute-replaced-height-007.htm.ini
@@ -1,4 +1,5 @@
 [absolute-replaced-height-007.htm]
   type: reftest
+  disabled: unstable
   expected:
     if (os == "linux") and (version == "Ubuntu 14.04"): FAIL
diff --git a/tests/wpt/metadata-css/css21_dev/html4/line-height-125.htm.ini b/tests/wpt/metadata-css/css21_dev/html4/line-height-125.htm.ini
index b06de08eb6b..9b6d8303eb8 100644
--- a/tests/wpt/metadata-css/css21_dev/html4/line-height-125.htm.ini
+++ b/tests/wpt/metadata-css/css21_dev/html4/line-height-125.htm.ini
@@ -1,5 +1,5 @@
 [line-height-125.htm]
   type: reftest
+  disabled: unstable
   expected:
-    if not debug and (os == "linux") and (version == "Ubuntu 14.04") and (processor == "x86_64") and (bits == 64): PASS
     FAIL