diff --git a/api/gtk-api.xml b/api/gtk-api.xml
index 971c3aaaa..057bcefd5 100644
--- a/api/gtk-api.xml
+++ b/api/gtk-api.xml
@@ -12590,7 +12590,7 @@
       <method name="Write" cname="gtk_html_stream_write">
         <return-type type="void"/>
         <parameters>
-          <parameter type="const-gchar*" name="buffer"/>
+          <parameter type="const-guchar*" name="buffer" array="1"/>
           <parameter type="size_t" name="size"/>
         </parameters>
       </method>