diff --git a/layout/reftests/text/reftest.list b/layout/reftests/text/reftest.list
index 3efb1cc4f76..58dea4654d7 100644
--- a/layout/reftests/text/reftest.list
+++ b/layout/reftests/text/reftest.list
@@ -45,6 +45,7 @@ fails-if(Android) skip-if(d2d||cocoaWidget) == subpixel-glyphs-x-1a.html subpixe
 # subpixel.
 # D2D/DirectWrite results depend on the rendering mode chosen, so considering this as random for now.
 skip-if(!(d2d||cocoaWidget)) random-if(d2d) != subpixel-glyphs-x-2a.html subpixel-glyphs-x-2b.html
+HTTP(..) == subpixel-glyphs-x-3a.html subpixel-glyphs-x-3b.html
 # No platforms do subpixel positioning vertically
 == subpixel-glyphs-y-1a.html subpixel-glyphs-y-1b.html
 == subpixel-lineheight-1a.html subpixel-lineheight-1b.html
diff --git a/layout/reftests/text/subpixel-glyphs-x-3a.html b/layout/reftests/text/subpixel-glyphs-x-3a.html
new file mode 100644
index 00000000000..34f8368d21d
--- /dev/null
+++ b/layout/reftests/text/subpixel-glyphs-x-3a.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+        <meta http-equiv="Content-Style-Type" content="text/css">
+        <title>Test for consistent kerning, bug 716402</title>
+        <style type="text/css">
+          @font-face {
+            font-family: mplus;
+            src: url(../fonts/mplus/mplus-1p-regular-no-OT.ttf);
+            /* a copy of M+ with OpenType tables removed,
+               so only legacy 'kern' is present */
+          }
+          body {
+             text-rendering: optimizeLegibility;
+             font-family: mplus;
+             font-size: 15px;
+             background: white;
+             color: black;
+          }
+          .right {
+             text-align: right;
+          }
+        </style>
+</head>
+<body>
+  <div>
+    AVAV
+  </div>
+  <div class="right">
+    AVAV
+  </div>
+</body>
diff --git a/layout/reftests/text/subpixel-glyphs-x-3b.html b/layout/reftests/text/subpixel-glyphs-x-3b.html
new file mode 100644
index 00000000000..83b5aa34dbf
--- /dev/null
+++ b/layout/reftests/text/subpixel-glyphs-x-3b.html
@@ -0,0 +1,36 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+        <meta http-equiv="Content-Style-Type" content="text/css">
+        <title>Reference for consistent kerning, bug 716402</title>
+        <style type="text/css">
+          @font-face {
+            font-family: mplus;
+            src: url(../fonts/mplus/mplus-1p-regular-no-OT.ttf);
+            /* a copy of M+ with OpenType tables removed,
+               so only legacy 'kern' is present */
+          }
+          body {
+             text-rendering: optimizeLegibility;
+             font-family: mplus;
+             font-size: 15px;
+             background: white;
+             color: black;
+          }
+          .right {
+             text-align: right;
+          }
+          span {
+             color: white;
+          }
+        </style>
+</head>
+<body>
+  <div>
+    AVAV<span>AV</span>
+  </div>
+  <div class="right">
+    <span>AV</span>AVAV
+  </div>
+</body>
