diff --git a/CHANGELOG.md b/CHANGELOG.md
index 30d7624..7eb73a4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased] -
 
+### Added
+- Add sample "404 not found page" to `/docs/404.html` and `/example/404.html`. [#12](https://github.com/mmistakes/jekyll-theme-basically-basic/issues/12)
+
 ### Changed
 - Adjust default skin colors to meet WCAG 2 AA. [#68](https://github.com/mmistakes/jekyll-theme-basically-basic/pull/68)
 
diff --git a/docs/404.md b/docs/404.md
new file mode 100644
index 0000000..3d36d17
--- /dev/null
+++ b/docs/404.md
@@ -0,0 +1,7 @@
+---
+title: Page not found
+layout: page
+permalink: /404.html
+---
+
+Sorry, but the page you were trying to view has moved or does not exist.
diff --git a/example/404.md b/example/404.md
new file mode 100644
index 0000000..3d36d17
--- /dev/null
+++ b/example/404.md
@@ -0,0 +1,7 @@
+---
+title: Page not found
+layout: page
+permalink: /404.html
+---
+
+Sorry, but the page you were trying to view has moved or does not exist.