diff --git a/site/docs/datafiles.md b/site/docs/datafiles.md
index fd6b0d51..05e59345 100644
--- a/site/docs/datafiles.md
+++ b/site/docs/datafiles.md
@@ -22,7 +22,7 @@ Plugins/themes can also leverage Data Files to set configuration variables.
 
 As explained on the [directory structure](../structure/) page, the `_data`
 folder is where you can store additional data for Jekyll to use when generating
-your site. These files must be YAML files (using either the `.yml`, `.yaml` or `json`
+your site. These files must be YAML files (using either the `.yml`, `.yaml` or `.json`
 extension) and they will be accessible via `site.data`.
 
 ## Example: List of members