diff --git a/source/Constants.js b/source/Constants.js
index b04172a..aeec0e2 100644
--- a/source/Constants.js
+++ b/source/Constants.js
@@ -34,7 +34,7 @@ var isIElt11 = /Trident\/[456]\./.test( ua );
 var isPresto = !!win.opera;
 var isEdge = /Edge\//.test( ua );
 var isWebKit = !isEdge && /WebKit\//.test( ua );
-var isIE = /MSIE/.test( ua );
+var isIE = /Trident\/[4567]\./.test( ua );
 
 var ctrlKey = isMac ? 'meta-' : 'ctrl-';