diff --git a/lib/xcore.js b/lib/xcore.js
index 59ddbdd..218c71d 100644
--- a/lib/xcore.js
+++ b/lib/xcore.js
@@ -235,7 +235,9 @@ XClient.prototype.AllocID = function()
 XClient.prototype.unpackEvent = function(type, seq, extra, code, raw)
 {
     var event = {}; // TODO: constructor & base functions
-    event.type = type;
+    // Remove the most significant bit. See Chapter 1, Event Format section in X11 protocol
+    // specification
+    event.type = type && 0x7F; 
     event.seq = seq;
 
     var extUnpacker = this.eventParsers[type];