diff --git a/layout/reftests/transform-3d/mask-layer-1.html b/layout/reftests/transform-3d/mask-layer-1.html
new file mode 100644
index 000000000000..834ed4463306
--- /dev/null
+++ b/layout/reftests/transform-3d/mask-layer-1.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<html lang="en">
+<meta charset="utf-8">
+<title>border-radius should work correctly for elements with perspective</title>
+
+<style>
+
+#a {
+  position: relative;
+  width: 300px;
+  height: 300px;
+  border-radius: 10px;
+  overflow: hidden;
+  background: red;
+  perspective: 1000px;
+}
+
+#b {
+  position: relative;
+  background: green;
+  height: 100%;
+  width: 10000px;
+  transform: translateX(0px);
+}
+</style>
+
+<div id="a">
+  <div id="b"></div>
+</div>
diff --git a/layout/reftests/transform-3d/mask-layer-2.html b/layout/reftests/transform-3d/mask-layer-2.html
new file mode 100644
index 000000000000..23315e224977
--- /dev/null
+++ b/layout/reftests/transform-3d/mask-layer-2.html
@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+<html lang="en">
+<meta charset="utf-8">
+<title>border-radius should work correctly for elements with perspective and preserve-3d</title>
+
+<style>
+
+#a {
+  position: relative;
+  width: 300px;
+  height: 300px;
+  border-radius: 10px;
+  overflow: hidden;
+  background: red;
+  perspective: 1000px;
+}
+
+#b {
+  height: 100%;
+  transform-style: preserve-3d;
+  transform: rotateX(90deg);
+}
+
+#c {
+  position: relative;
+  background: green;
+  height: 100%;
+  width: 10000px;
+  transform: rotateX(90deg);
+}
+</style>
+
+<div id="a">
+  <div id="b">
+    <div id="c"></div>
+  </div>
+</div>
diff --git a/layout/reftests/transform-3d/mask-layer-3.html b/layout/reftests/transform-3d/mask-layer-3.html
new file mode 100644
index 000000000000..58a04a45abe6
--- /dev/null
+++ b/layout/reftests/transform-3d/mask-layer-3.html
@@ -0,0 +1,36 @@
+<!DOCTYPE html>
+<html lang="en">
+<meta charset="utf-8">
+<title>border-radius should work correctly for elements with preserve-3d</title>
+
+<style>
+
+#a {
+  position: relative;
+  width: 300px;
+  height: 300px;
+  border-radius: 10px;
+  overflow: hidden;
+  background: red;
+}
+
+#b {
+  height: 100%;
+  transform-style: preserve-3d;
+  transform: rotateX(90deg);
+}
+
+#c {
+  position: relative;
+  background: green;
+  height: 100%;
+  width: 10000px;
+  transform: rotateX(90deg);
+}
+</style>
+
+<div id="a">
+  <div id="b">
+    <div id="c"></div>
+  </div>
+</div>
diff --git a/layout/reftests/transform-3d/mask-layer-ref.html b/layout/reftests/transform-3d/mask-layer-ref.html
new file mode 100644
index 000000000000..bc4f963e63fd
--- /dev/null
+++ b/layout/reftests/transform-3d/mask-layer-ref.html
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<html lang="en">
+<meta charset="utf-8">
+<title>border-radius should work correctly for transformed elements</title>
+
+<style>
+
+#a {
+  position: relative;
+  width: 300px;
+  height: 300px;
+  border-radius: 10px;
+  overflow: hidden;
+  background: red;
+}
+
+#b {
+  position: relative;
+  background: green;
+  height: 100%;
+  width: 10000px;
+  transform: translateZ(1px);
+}
+</style>
+
+<div id="a">
+  <div id="b"></div>
+</div>
diff --git a/layout/reftests/transform-3d/reftest.list b/layout/reftests/transform-3d/reftest.list
index b762474d68dd..b328a0808e65 100644
--- a/layout/reftests/transform-3d/reftest.list
+++ b/layout/reftests/transform-3d/reftest.list
@@ -78,3 +78,6 @@ fuzzy(1,15000) == opacity-preserve3d-2.html opacity-preserve3d-2-ref.html
 fuzzy(1,10000) == opacity-preserve3d-3.html opacity-preserve3d-3-ref.html
 fuzzy(1,10000) == opacity-preserve3d-4.html opacity-preserve3d-4-ref.html
 == snap-perspective-1.html snap-perspective-1-ref.html
+== mask-layer-1.html mask-layer-ref.html
+== mask-layer-2.html mask-layer-ref.html
+== mask-layer-3.html mask-layer-ref.html
