diff --git a/resources/cert-wpt-only b/resources/cert-wpt-only
new file mode 100644
index 00000000000..8d1bc0f7ca0
--- /dev/null
+++ b/resources/cert-wpt-only
@@ -0,0 +1,20 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/tests/wpt/README.md b/tests/wpt/README.md
index 26c9639d627..1c0434f494d 100644
--- a/tests/wpt/README.md
+++ b/tests/wpt/README.md
@@ -94,7 +94,11 @@ defaults at `config.default.json`) with the following contents:
     }
 
 Finally, you can run `python serve` from `tests/wpt/web-platform-tests`.
-Then navigate Servo to `http://web-platform.test:8000/path/to/test`.
+Then navigate Servo to `http://web-platform.test:8000/path/to/test` or
+`https://web-platform.test:8443/path/to/test`.
+
+To prevent browser SSL warnings when running HTTPS tests locally,
+you will need to run Servo with `--certificate-path resources/cert-wpt-only`.
 
 [upstream-running]: https://github.com/w3c/web-platform-tests#running-the-tests