1 files changed, 2 insertions, 0 deletions
diff --git a/js/xal.js b/js/xal.js
index 17c98f3..1ac06b7 100644
--- a/js/xal.js
+++ b/js/xal.js
@@ -23,6 +23,8 @@
 
 /* global chrome, ηMatrix */
 
+'use strict';
+
 /******************************************************************************/
 
 ηMatrix.XAL = (function(){