diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 9695a3885..fe95e28ec 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -394,7 +394,7 @@ In your local copy, make a branch for this change using a descriptive branch nam
 Make your changes to source files under `modules/`.
 The `iD.js` and `iD.min.js` files in this project are autogenerated - don't edit them.
 
-1. Try your change locally.  Run `npm start` and visit `localhost:8080` in a browser.
+1. Try your change locally.  Run `npm start` and visit `http://127.0.0.1:8080` in a browser.
 2. Run lint and tests with `npm test`.
 3. If you feel like it, append a line describing your changes to the project's [changelog](https://github.com/openstreetmap/iD/blob/develop/CHANGELOG.md).
 4. Commit your changes with an informative commit message.
diff --git a/README.md b/README.md
index 55ff0e433..66bf34e00 100644
--- a/README.md
+++ b/README.md
@@ -67,7 +67,7 @@ If you want to add in the full history later on, perhaps to run `git blame` or `
 2. Run `npm install`
 3. Run `npm run all`
 3. Run `npm start`
-4. Open `http://localhost:8080/` in a web browser
+4. Open `http://127.0.0.1:8080/` in a web browser
 
 For guidance on building a packaged version, running tests, and contributing to
 development, see [CONTRIBUTING.md](CONTRIBUTING.md).