diff --git a/layout/generic/crashtests/520340.html b/layout/generic/crashtests/520340.html
new file mode 100644
index 00000000000..2b8dc007735
--- /dev/null
+++ b/layout/generic/crashtests/520340.html
@@ -0,0 +1,2 @@
+<!DOCTYPE HTML>
+<html style="-moz-column-width: 1px;"><head></head><body style="-moz-column-count: 2;">A B C D E F<span>&#x7E01;</span></body></html>
diff --git a/layout/generic/crashtests/533379-1.html b/layout/generic/crashtests/533379-1.html
new file mode 100644
index 00000000000..a232b19cd1d
--- /dev/null
+++ b/layout/generic/crashtests/533379-1.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html>
+<head>
+<style>
+body { width: 1px; }
+ul { -moz-column-count: 15; }
+li  {list-style-position: inside; }
+li:first-letter {color: red; }
+</style>
+</head>
+
+<body>
+<ul><li><span>A B</span></li></ul>
+</body>
+
+</html>
diff --git a/layout/generic/crashtests/533379-2.html b/layout/generic/crashtests/533379-2.html
new file mode 100644
index 00000000000..56311993cd9
--- /dev/null
+++ b/layout/generic/crashtests/533379-2.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html>
+<head>
+<style>
+body { width: 1px; }
+ul { -moz-column-count: 2; }
+li  {list-style-position: inside; }
+li:first-letter {color: red; }
+</style>
+</head>
+
+<body>
+<ul><li><span>A B</span></li></ul>
+</body>
+
+</html>
diff --git a/layout/generic/crashtests/crashtests.list b/layout/generic/crashtests/crashtests.list
index 75e2f02abdc..877e8454a07 100644
--- a/layout/generic/crashtests/crashtests.list
+++ b/layout/generic/crashtests/crashtests.list
@@ -280,3 +280,6 @@ load 505912-1.html
 load 511482.html
 load 513394-1.html
 load 517968.html
+load 520340.html
+load 533379-1.html
+load 533379-2.html
