diff --git a/css/css-ruby/break-within-bases/no-break-opportunity-at-end-ref.html b/css/css-ruby/break-within-bases/no-break-opportunity-at-end-ref.html
new file mode 100644
index 00000000000000..f69f8d9456f04e
--- /dev/null
+++ b/css/css-ruby/break-within-bases/no-break-opportunity-at-end-ref.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<style>
+div {
+  font-size: 20px;
+}
+</style>
+
+<body lang="ja">
+<div>
+ここは<ruby>優先通行<rt>ゆうせんつうこう</ruby><br><ruby>帯<rt>たい</ruby>。
+</div>
+</body>
diff --git a/css/css-ruby/break-within-bases/no-break-opportunity-at-end.html b/css/css-ruby/break-within-bases/no-break-opportunity-at-end.html
new file mode 100644
index 00000000000000..83a05b3dce46fd
--- /dev/null
+++ b/css/css-ruby/break-within-bases/no-break-opportunity-at-end.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<link rel="help" href="https://drafts.csswg.org/css-ruby/#break-within">
+<link rel="match" href="no-break-opportunity-at-end-ref.html">
+<style>
+div {
+  width: 160px;
+  font-size: 20px;
+}
+</style>
+
+<body lang="ja">
+
+<!-- The ruby fits in the first line, but we can not break
+     the line at its end because of the following "。". -->
+<div>
+ここは<ruby>優先通行帯<rt>ゆうせんつうこうたい</ruby>。
+</div>
+</body>
