diff --git a/layout/base/crashtests/388715-1.html b/layout/base/crashtests/388715-1.html
new file mode 100644
index 00000000000..be09591f8d9
--- /dev/null
+++ b/layout/base/crashtests/388715-1.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<html>
+<head>
+
+<style type="text/css">
+#div:first-letter { float: left; color: lightgreen; }
+</style>
+
+<script type="text/javascript">
+function boom()
+{
+  document.getElementById("div").className = "anything";
+}
+</script>
+</head>
+
+<body onload="boom()">
+
+<div id="div"><span style="color: magenta">Foo</span> bar</div>
+
+</body>
+</html>
diff --git a/layout/base/crashtests/crashtests.list b/layout/base/crashtests/crashtests.list
index 7c94ef49734..ded27ab5060 100644
--- a/layout/base/crashtests/crashtests.list
+++ b/layout/base/crashtests/crashtests.list
@@ -64,6 +64,7 @@ load 382204-1.html
 load 383806-1.xhtml
 load 385866-1.xhtml
 load 385880-1.xhtml
+load 388715-1.html
 load 390976-1.html
 load 393661-1.html
 load 393801-1.html
