diff --git a/lib/x11/corereqs.js b/lib/x11/corereqs.js
index bcdae15..e3eeaea 100644
--- a/lib/x11/corereqs.js
+++ b/lib/x11/corereqs.js
@@ -104,7 +104,8 @@ the way requests are described here
 module.exports = {
    CreateWindow: [
        // create request packet - function OR format string
-       function(id, parentId, x, y, width, height, borderWidth, class, visual, values) {
+       function(id, parentId, x, y, width, height, borderWidth, _class, visual, values) {
+           console.log('CreateWindow called', id);
 
            // TODO: ??? there is depth field in xproto, but xlib just sets it to zero
            var depth = 0;
@@ -116,7 +117,7 @@ module.exports = {
            // create bitmask
            var bitmask = 0;
            // TODO: slice from function arguments?
-           var args = [1, depth, packetLength, id, parentId, x, y, width, height, borderWidth, class, visual];
+           var args = [1, depth, packetLength, id, parentId, x, y, width, height, borderWidth, _class, visual];
            
            // TODO: the code is a little bit mess
            // additional values need to be packed in the following way: