diff --git a/accessible/tests/mochitest/tree/test_tabbrowser.xul b/accessible/tests/mochitest/tree/test_tabbrowser.xul
index d4755c120fc..cb2c3a343a3 100644
--- a/accessible/tests/mochitest/tree/test_tabbrowser.xul
+++ b/accessible/tests/mochitest/tree/test_tabbrowser.xul
@@ -98,6 +98,16 @@
               // xul:tab ("about:")
               role: ROLE_PAGETAB,
               children: [
+                {
+                  // :before and :after image
+                  // (selected tab border on left/right)
+                  role: ROLE_GRAPHIC,
+                  children: []
+                },
+                {
+                  role: ROLE_GRAPHIC,
+                  children: []
+                },
                 {
                   // xul:toolbarbutton ("Close Tab")
                   role: ROLE_PUSHBUTTON,
@@ -113,6 +123,11 @@
                   // xul:toolbarbutton ("Close Tab")
                   role: ROLE_PUSHBUTTON,
                   children: []
+                },
+                {
+                  // :after image (separator)
+                  role: ROLE_GRAPHIC,
+                  children: []
                 }
               ]
             },