diff --git a/tests/assets/bg-sliver.png b/tests/assets/bg-sliver.png
new file mode 100644
index 0000000..06ed91f
Binary files /dev/null and b/tests/assets/bg-sliver.png differ
diff --git a/tests/reftests/background/size.html b/tests/reftests/background/size.html
index 6cdf0fc..d551136 100644
--- a/tests/reftests/background/size.html
+++ b/tests/reftests/background/size.html
@@ -9,6 +9,10 @@
             display: block;
             background:url("../../assets/image.jpg") center center;
         }
+        .sliver div {
+            background:url("../../assets/bg-sliver.png") center center;
+            background-size: 650px auto;
+        }
 
         .vertical {
             float: right;
@@ -57,5 +61,8 @@
     <div style='background-size: auto;'></div>
 </div>
 <div class="container" style="padding: 10px; background-size: contain; background-origin: content-box; background-clip: content-box"></div>
+<div class="sliver">
+    <div></div>
+</div>
 </body>
 </html>