diff --git a/mozilla/layout/html/tests/block/base/intrinsic-with-box-sizing-strict.html b/mozilla/layout/html/tests/block/base/intrinsic-with-box-sizing-strict.html
new file mode 100644
index 00000000000..2acffa2d9f1
--- /dev/null
+++ b/mozilla/layout/html/tests/block/base/intrinsic-with-box-sizing-strict.html
@@ -0,0 +1,19 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
+<html>
+<body>
+<div style="float: left; border: 1px solid red">
+<div style="padding: 50px; width: 200px; border: 25px solid green">
+</div>
+</div>
+
+<div style="float: left; border: 1px solid red">
+<div style="padding: 50px; width: 200px; border: 25px solid green; -moz-box-sizing: padding-box">
+</div>
+</div>
+
+<div style="float: left; border: 1px solid red">
+<div style="padding: 50px; width: 200px; border: 25px solid green; -moz-box-sizing: border-box">
+</div>
+</div>
+</body>
+</html>
diff --git a/mozilla/layout/html/tests/block/base/intrinsic-with-box-sizing.html b/mozilla/layout/html/tests/block/base/intrinsic-with-box-sizing.html
new file mode 100644
index 00000000000..22d50361906
--- /dev/null
+++ b/mozilla/layout/html/tests/block/base/intrinsic-with-box-sizing.html
@@ -0,0 +1,18 @@
+<html>
+<body>
+<div style="float: left; border: 1px solid red">
+<div style="padding: 50px; width: 200px; border: 25px solid green">
+</div>
+</div>
+
+<div style="float: left; border: 1px solid red">
+<div style="padding: 50px; width: 200px; border: 25px solid green; -moz-box-sizing: padding-box">
+</div>
+</div>
+
+<div style="float: left; border: 1px solid red">
+<div style="padding: 50px; width: 200px; border: 25px solid green; -moz-box-sizing: border-box">
+</div>
+</div>
+</body>
+</html>
