diff --git a/cookies/secure/set-from-dom.sub.html b/cookies/secure/set-from-dom.sub.html
new file mode 100644
index 00000000000000..91aa8fff3b706c
--- /dev/null
+++ b/cookies/secure/set-from-dom.sub.html
@@ -0,0 +1,47 @@
+<!doctype html>
+<html>
+<head>
+  <meta charset=utf-8>
+  <title>Set 'secure' cookie from `document.cookie` on a non-secure page</title>
+  <meta name=help href="https://tools.ietf.org/html/draft-west-leave-secure-cookies-alone">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/cookies/resources/testharness-helpers.js"></script>
+</head>
+<body>
+<div id=log></div>
+<script>
+  var tests = [
+    [
+      "'secure' cookie not set in `document.cookie`",
+      function () {
+        var originalCookie = document.cookie;
+        document.cookie = "secure_from_nonsecure_dom=1; secure; path=/";
+        assert_equals(document.cookie, originalCookie);
+        this.done();
+      }
+    ],
+    [
+      "'secure' cookie not sent in HTTP request",
+      function () {
+        document.cookie = "secure_from_nonsecure_dom=1; secure; path=/";
+        fetch("https://{{host}}:{{ports[https][0]}}/cookies/resources/echo-json.py", { "credentials": "include" })
+          .then(this.step_func(function (r) {
+              return r.json();
+          }))
+          .then(this.step_func_done(function (j) {
+              assert_equals(j["secure_from_nonsecure_dom"], undefined);
+          }));
+      }
+    ]
+  ];
+
+  function clearKnownCookie() {
+    document.cookie = "secure_from_nonsecure_dom=0; Secure; expires=Thu, 01 Jan 1970 00:00:01 GMT; path=/";
+  }
+
+  executeTestsSerially(tests, clearKnownCookie, clearKnownCookie);
+</script>
+</body>
+</html>
+
diff --git a/cookies/secure/set-from-http.sub.html b/cookies/secure/set-from-http.sub.html
new file mode 100644
index 00000000000000..c80cc341017b5b
--- /dev/null
+++ b/cookies/secure/set-from-http.sub.html
@@ -0,0 +1,36 @@
+<!doctype html>
+<html>
+<head>
+  <meta charset=utf-8>
+  <title>Set 'secure' cookie from `Set-Cookie` HTTP header on a non-secure page</title>
+  <meta name=help href="https://tools.ietf.org/html/draft-west-leave-secure-cookies-alone">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/cookies/resources/testharness-helpers.js"></script>
+</head>
+<body>
+<div id=log></div>
+<script>
+  function clearKnownCookie() {
+    document.cookie = "secure_from_nonsecure_http=0; Secure; expires=Thu, 01 Jan 1970 00:00:01 GMT; path=/";
+  }
+
+  test(function () {
+    assert_equals(document.cookie.match(/secure_from_nonsecure_http=1/), null);
+  }, "'secure' cookie not present in `document.cookie`");
+
+  promise_test(function (t) {
+    t.add_cleanup(clearKnownCookie);
+    return fetch("https://{{host}}:{{ports[https][0]}}/cookies/resources/echo-json.py",
+                 { "credentials": "include" })
+      .then(function (r) {
+        return r.json();
+      })
+      .then(function (j) {
+        assert_equals(j["secure_from_nonsecure_http"], undefined);
+      });
+  }, "'secure' cookie not sent in HTTP request");
+</script>
+</body>
+</html>
+
