diff --git a/docs/newgrf-additions.html b/docs/newgrf-additions.html
index 7fc2890372..8e3ea8d954 100644
--- a/docs/newgrf-additions.html
+++ b/docs/newgrf-additions.html
@@ -121,7 +121,7 @@
 	<tr><td>V</td><td>data</td><td>Property data</td></tr>
 	</table>
 	Note that num is an extended byte, see <a href="https://newgrf-specs.tt-wiki.net/wiki/GRFActionsDetailed">GRFActionsDetailed</a>.<br />
-	If the size of the data does provided is not valid for the given property, the attempt to set the property MAY be ignored or partially applied.<br />
+	If the size of the data provided is not valid for the given property, the attempt to set the property MAY be ignored or partially applied.<br />
 	Note that each use of the mapped property ID is followed by Num-info iterations of the size and data pair above. See: <a href="https://newgrf-specs.tt-wiki.net/wiki/Action0">Action 0 Specification</a>.
 	<h4>Example NFO:</h4>
 	<pre>