diff --git a/include/xtscancodes.js b/include/xtscancodes.js
index d19a0174..489d17a1 100644
--- a/include/xtscancodes.js
+++ b/include/xtscancodes.js
@@ -110,6 +110,8 @@ XtScancode["ArrowDown"] = 0xE050;
 XtScancode["PageDown"] = 0xE051;
 XtScancode["Insert"] = 0xE052;
 XtScancode["Delete"] = 0xE053;
+XtScancode["MetaLeft"] = 0xE05B;
+XtScancode["MetaRight"] = 0xE05C;
 XtScancode["OSLeft"] = 0xE05B;
 XtScancode["OSRight"] = 0xE05C;
 XtScancode["ContextMenu"] = 0xE05D;