diff --git a/sources/Gtk.metadata b/sources/Gtk.metadata
index 4084adc97..68a164b8e 100644
--- a/sources/Gtk.metadata
+++ b/sources/Gtk.metadata
@@ -1299,6 +1299,18 @@ z<rule>
     </attribute>
   </data>
 </rule>
+<rule>
+  <class name="GtkHTMLStream">
+    <method>Write</method>
+  </class>
+  <data>
+    <attribute target="param">
+      <filter level="type">const-gchar*</filter>
+      <name>array</name>
+      <value>1</value>
+    </attribute>
+  </data>
+</rule>
 
 <!-- hides -->
 <rule>