diff --git a/layout/reftests/bugs/902330-1-ref.html b/layout/reftests/bugs/902330-1-ref.html
new file mode 100644
index 000000000000..fbf6a9b27ad2
--- /dev/null
+++ b/layout/reftests/bugs/902330-1-ref.html
@@ -0,0 +1,24 @@
+<html>
+<head>
+<style>
+canvas {
+  position: absolute;
+  top: 100px;
+  left: 100px;
+  width: 300px;
+  height: 300px;
+}
+</style>
+</head>
+<body>
+<canvas id="c" height="300px" width="300px"></canvas>
+<script>
+var c = document.getElementById('c');
+var ctxt = c.getContext('2d');
+ctxt.fillStyle = 'rgb(0,255,0)';
+ctxt.fillRect(0, 0, 300, 300);
+ctxt.fillStyle = 'rgba(255,255,255,0.5)';
+ctxt.fillRect(100, 100, 100, 100);
+</script>
+</body>
+</html>
diff --git a/layout/reftests/bugs/902330-1.html b/layout/reftests/bugs/902330-1.html
new file mode 100644
index 000000000000..338908ba6eb2
--- /dev/null
+++ b/layout/reftests/bugs/902330-1.html
@@ -0,0 +1,33 @@
+<html>
+<head>
+<style>
+canvas {
+  position: absolute;
+  top: 100px;
+  left: 100px;
+  width: 300px;
+  height: 300px;
+}
+div.inner {
+  position: absolute;
+  top: 200px;
+  left: 200px;
+  width: 100px;
+  height: 100px;
+  opacity: 0.5;
+  background-color: #ffffff;
+}
+</style>
+</head>
+<body>
+<canvas id="c" height="300px" width="300px"></canvas>
+<script>
+var c = document.getElementById('c');
+var ctxt = c.getContext('2d');
+ctxt.fillStyle = 'rgb(0,255,0)';
+ctxt.fillRect(0, 0, 300, 300);
+</script>
+<div class="inner">
+</div>
+</body>
+</html>
diff --git a/layout/reftests/bugs/reftest.list b/layout/reftests/bugs/reftest.list
index e1e4d5973317..c79d2d1a01bf 100644
--- a/layout/reftests/bugs/reftest.list
+++ b/layout/reftests/bugs/reftest.list
@@ -1772,5 +1772,6 @@ test-pref(layout.css.flexbox.enabled,true) == 849407-1.html 849407-1-ref.html
 == 883987-1f.html 883987-1-ref.html
 == 890495-1.html 890495-1-ref.html
 == 894931-1.html 894931-1-ref.html
+fuzzy(1,10000) == 902330-1.html 902330-1-ref.html
 == 897491-1.html 897491-1-ref.html
 == 897491-2.html 897491-2-ref.html
