diff --git a/docs/contributing/ui_guidelines.md b/docs/contributing/ui_guidelines.md
index ea420d367d..19e79b68c5 100644
--- a/docs/contributing/ui_guidelines.md
+++ b/docs/contributing/ui_guidelines.md
@@ -1,4 +1,4 @@
-# UI Guidelines
+# UI guidelines
 
 Wagtail’s user interface is built with: