diff --git a/Assets/WebGLSupport/WebGLInput/WebGLInput.jslib b/Assets/WebGLSupport/WebGLInput/WebGLInput.jslib
index 83a696d..a6454ae 100644
--- a/Assets/WebGLSupport/WebGLInput/WebGLInput.jslib
+++ b/Assets/WebGLSupport/WebGLInput/WebGLInput.jslib
@@ -159,14 +159,16 @@ var WebGLInput = {
     WebGLInputOnKeyboardEvent:function(id, cb){
         var input = instances[id];
         var func = function(mode, e) {
-            var bufferSize = lengthBytesUTF8(e.key) + 1;
-            var key = _malloc(bufferSize);
-            stringToUTF8(e.key, key, bufferSize);
-            var code = e.code;
-            var shift = e.shiftKey ? 1 : 0;
-            var ctrl = e.ctrlKey ? 1 : 0;
-            var alt = e.altKey ? 1 : 0;
-            (!!Runtime.dynCall) ? Runtime.dynCall("viiiiiii", cb, [id, mode, key, code, shift, ctrl, alt]) : {{{ makeDynCall("viiiiiii", "cb") }}}(id, mode, key, code, shift, ctrl, alt);
+            if (e instanceof KeyboardEvent){
+                var bufferSize = lengthBytesUTF8(e.key) + 1;
+                var key = _malloc(bufferSize);
+                stringToUTF8(e.key, key, bufferSize);
+                var code = e.code;
+                var shift = e.shiftKey ? 1 : 0;
+                var ctrl = e.ctrlKey ? 1 : 0;
+                var alt = e.altKey ? 1 : 0;
+                (!!Runtime.dynCall) ? Runtime.dynCall("viiiiiii", cb, [id, mode, key, code, shift, ctrl, alt]) : {{{ makeDynCall("viiiiiii", "cb") }}}(id, mode, key, code, shift, ctrl, alt);
+            }
         }
         input.addEventListener('keydown', function(e) { func(1, e); });
         input.addEventListener('keyup', function(e) { func(2, e); });