diff --git a/layout/reftests/font-matching/reftest.list b/layout/reftests/font-matching/reftest.list
index 1c0ac3103cf..a4585fda251 100644
--- a/layout/reftests/font-matching/reftest.list
+++ b/layout/reftests/font-matching/reftest.list
@@ -70,3 +70,8 @@ HTTP(..) == stretchmapping-137.html stretchmapping-137-ref.html
 # test for font-stretch using @font-face
 HTTP(..) == font-stretch-1.html font-stretch-1-ref.html
 
+# bug 724231 - applying synthetic styles to a single @font-face font
+# should apply artificial obliquing, not switch to a true styled face
+!= synthetic-style-1.html synthetic-style-1-notref.html
+!= synthetic-style-2.html synthetic-style-2-notref.html
+
diff --git a/layout/reftests/font-matching/synthetic-style-1-notref.html b/layout/reftests/font-matching/synthetic-style-1-notref.html
new file mode 100644
index 00000000000..0cc51da48fa
--- /dev/null
+++ b/layout/reftests/font-matching/synthetic-style-1-notref.html
@@ -0,0 +1,15 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<title>Synthetic italic should not use true italic face</title>
+<!-- see bug 724231 -->
+<style type="text/css">
+body {
+  font-family: "Times New Roman", "Times", "DejaVu Serif", "FreeSerif", "Droid Serif", sans-serif;
+}
+</style>
+</head>
+<body>
+<p><i>Synthetic italics</i> should <i>not</i> use the true italic face.
+</body>
+</html>
diff --git a/layout/reftests/font-matching/synthetic-style-1.html b/layout/reftests/font-matching/synthetic-style-1.html
new file mode 100644
index 00000000000..4db379273c4
--- /dev/null
+++ b/layout/reftests/font-matching/synthetic-style-1.html
@@ -0,0 +1,19 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<title>Synthetic italic should not use true italic face</title>
+<!-- see bug 724231 -->
+<style type="text/css">
+@font-face {
+  font-family: test;
+  src: local(Times New Roman), local(Times), local(DejaVu Serif), local(FreeSerif), local(Droid Serif);
+}
+body {
+  font-family: test, sans-serif;
+}
+</style>
+</head>
+<body>
+<p><i>Synthetic italics</i> should <i>not</i> use the true italic face.
+</body>
+</html>
diff --git a/layout/reftests/font-matching/synthetic-style-2-notref.html b/layout/reftests/font-matching/synthetic-style-2-notref.html
new file mode 100644
index 00000000000..e3fa7fb6af6
--- /dev/null
+++ b/layout/reftests/font-matching/synthetic-style-2-notref.html
@@ -0,0 +1,15 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<title>Synthetic bold should not use true bold face</title>
+<!-- see bug 724231 -->
+<style type="text/css">
+body {
+  font-family: "Times New Roman", "Times", "DejaVu Serif", "FreeSerif", "Droid Serif", sans-serif;
+}
+</style>
+</head>
+<body>
+<p><b>Synthetic bold</b> should <b>not</b> use the true bold face.
+</body>
+</html>
diff --git a/layout/reftests/font-matching/synthetic-style-2.html b/layout/reftests/font-matching/synthetic-style-2.html
new file mode 100644
index 00000000000..3885119112a
--- /dev/null
+++ b/layout/reftests/font-matching/synthetic-style-2.html
@@ -0,0 +1,19 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<title>Synthetic bold should not use true bold face</title>
+<!-- see bug 724231 -->
+<style type="text/css">
+@font-face {
+  font-family: test;
+  src: local(Times New Roman), local(Times), local(DejaVu Serif), local(FreeSerif), local(Droid Serif);
+}
+body {
+  font-family: test, sans-serif;
+}
+</style>
+</head>
+<body>
+<p><b>Synthetic bold</b> should <b>not</b> use the true bold face.
+</body>
+</html>
