diff --git a/keymaster.js b/keymaster.js
index 23c44e5..ee85d32 100644
--- a/keymaster.js
+++ b/keymaster.js
@@ -43,6 +43,16 @@
     return -1;
   }
 
+  var modifierMap = {
+      16:'shiftKey',
+      18:'altKey',
+      17:'ctrlKey',
+      91:'metaKey'
+  };
+  function updateModifierKey(event) {
+      for(k in _mods) _mods[k] = event[modifierMap[k]];
+  };
+
   // handle keydown event
   function dispatch(event, scope){
     var key, handler, k, i, modifiersMatch;
@@ -60,6 +70,7 @@
       for(k in _MODIFIERS) if(_MODIFIERS[k] == key) assignKey[k] = true;
       return;
     }
+    updateModifierKey(event);
 
     // see if we need to ignore the keypress (filter() can can be overridden)
     // by default ignore key presses if a select, textarea, or input is focused
diff --git a/test/keymaster.html b/test/keymaster.html
index a22c70e..40d4483 100644
--- a/test/keymaster.html
+++ b/test/keymaster.html
@@ -21,14 +21,23 @@ <h1>Keymaster unit tests</h1>
       return document.getElementById(id);
     }
 
+    var modifierMap = {
+      16:'shiftKey',
+      18:'altKey',
+      17:'ctrlKey',
+      91:'metaKey'
+    };
+
     // because the DOM is retarded,
     // and browsers don't really care about the DOM API anyway
     // (IE, Firefox, WebKit are all using different event generators),
     // we'll just simulate events roughly
-    function keydown(code, el){
+    function keydown(code, modifiers, el){
       var event = document.createEvent('Event');
       event.initEvent('keydown', true, true);
       event.keyCode = code;
+      if (modifiers && modifiers.length > 0)
+          for(i in modifiers) event[modifierMap[modifiers[i]]] = true;
       (el||document).dispatchEvent(event);
     }
 
@@ -73,14 +82,14 @@ <h1>Keymaster unit tests</h1>
         t.assertEqual(0, cntCommandCtrlShiftA);
         t.assertEqual(0, cntCommandCtrlAltShiftA);
 
-        keydown(KEYS.shift); keydown(65); keyup(65); keyup(KEYS.shift);
+        keydown(KEYS.shift); keydown(65, [16]); keyup(65); keyup(KEYS.shift);
         t.assertEqual(1, cntA);
         t.assertEqual(1, cntShiftA);
         t.assertEqual(0, cntCtrlShiftA);
         t.assertEqual(0, cntCommandCtrlShiftA);
         t.assertEqual(0, cntCommandCtrlAltShiftA);
 
-        keydown(KEYS.shift); keydown(KEYS.ctrl); keydown(65); keyup(65); keyup(KEYS.shift); keyup(KEYS.ctrl);
+        keydown(KEYS.shift); keydown(KEYS.ctrl); keydown(65, [16, 17]); keyup(65); keyup(KEYS.shift); keyup(KEYS.ctrl);
         t.assertEqual(1, cntA);
         t.assertEqual(1, cntShiftA);
         t.assertEqual(1, cntCtrlShiftA);
@@ -88,7 +97,7 @@ <h1>Keymaster unit tests</h1>
         t.assertEqual(0, cntCommandCtrlAltShiftA);
 
         keydown(KEYS.command); keydown(KEYS.shift); keydown(KEYS.ctrl);
-        keydown(65); keyup(65);
+        keydown(65, [91, 16, 17]); keyup(65);
         keyup(KEYS.shift); keyup(KEYS.ctrl); keyup(KEYS.command);
         t.assertEqual(1, cntA);
         t.assertEqual(1, cntShiftA);
@@ -97,7 +106,7 @@ <h1>Keymaster unit tests</h1>
         t.assertEqual(0, cntCommandCtrlAltShiftA);
 
         keydown(KEYS.alt); keydown(KEYS.command); keydown(KEYS.shift); keydown(KEYS.ctrl);
-        keydown(65); keyup(65);
+        keydown(65, [18, 91, 16, 17]); keyup(65);
         keyup(KEYS.shift); keyup(KEYS.ctrl); keyup(KEYS.command); keyup(KEYS.alt);
         t.assertEqual(1, cntA);
         t.assertEqual(1, cntShiftA);
@@ -113,10 +122,10 @@ <h1>Keymaster unit tests</h1>
         key('⇧+c', function(){ sequence += 'c' });
         key('⌘+d', function(){ sequence += 'd' });
 
-        keydown(KEYS.ctrl); keydown(65); keyup(65); keyup(KEYS.ctrl);
-        keydown(KEYS.option); keydown(66); keyup(66); keyup(KEYS.option);
-        keydown(KEYS.shift); keydown(67); keyup(67); keyup(KEYS.shift);
-        keydown(KEYS.command); keydown(68); keyup(68); keyup(KEYS.command);
+        keydown(KEYS.ctrl); keydown(65, [17]); keyup(65); keyup(KEYS.ctrl);
+        keydown(KEYS.option); keydown(66, [18]); keyup(66); keyup(KEYS.option);
+        keydown(KEYS.shift); keydown(67, [16]); keyup(67); keyup(KEYS.shift);
+        keydown(KEYS.command); keydown(68, [91]); keyup(68); keyup(KEYS.command);
 
         t.assertEqual('abcd', sequence);
       },