diff --git a/gtk/inspector/css-editor.ui b/gtk/inspector/css-editor.ui
index c1163efba4..18eb32d8e7 100644
--- a/gtk/inspector/css-editor.ui
+++ b/gtk/inspector/css-editor.ui
@@ -41,6 +41,9 @@
         </child>
       </object>
     </child>
+    <child>
+      <object class="GtkSeparator"/>
+    </child>
     <child>
       <object class="GtkScrolledWindow">
         <property name="hscrollbar-policy">never</property>