diff --git a/lib/x11/corereqs.js b/lib/x11/corereqs.js
index 8b5a221..6fcab01 100644
--- a/lib/x11/corereqs.js
+++ b/lib/x11/corereqs.js
@@ -385,6 +385,14 @@ module.exports = {
            return res;
        }
    ],
+   
+   SetInputFocus: [
+
+      function (wid, revertTo) // revertTo: 0 - None, 1 - PointerRoot, 2 - Parent
+      {
+          return [ 'CCSLL', [42, revertTo, 3, wid, 0] ];
+      }
+   ],
 
    WarpPointer: [