diff --git a/guide/docs/extensions/itemBuilder.md b/guide/docs/extensions/itembuilder.md
similarity index 100%
rename from guide/docs/extensions/itemBuilder.md
rename to guide/docs/extensions/itembuilder.md
diff --git a/guide/mkdocs.yml b/guide/mkdocs.yml
index ee27ddd7..555a56e3 100644
--- a/guide/mkdocs.yml
+++ b/guide/mkdocs.yml
@@ -37,4 +37,4 @@ nav:
   - Extensions:
       - Event listener: extensions/listener.md
       - Tasks: extensions/tasks.md
-      - Item Builder: extensions/itemBuilder.md
+      - Item builder: extensions/itembuilder.md