diff --git a/toolkit/moz.configure b/toolkit/moz.configure
index a78a32bdc0c94..8a9609004b010 100644
--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -1193,6 +1193,7 @@ def x11_libs(webrtc):
             "xdamage",
             "xfixes",
             "xi",
+            "xtst",
         ]
     return libs