diff --git a/lib/x11/corereqs.js b/lib/x11/corereqs.js
index af2c8cd..a7b0ffc 100644
--- a/lib/x11/corereqs.js
+++ b/lib/x11/corereqs.js
@@ -229,7 +229,6 @@ module.exports = {
               format += 'S';
               args.push(points[i]);
           }
-          console.error([format, args]);
           return [format, args];
        }
    ],
@@ -245,7 +244,6 @@ module.exports = {
               format += 'S';
               args.push(points[i]);
           }
-          console.error([format, args]);
           return [format, args];
        }
        
@@ -285,6 +283,24 @@ module.exports = {
        }
    ],
    
+   QueryExtension: [
+       function(name) {
+           var padded = xutil.padded_string(name);
+           return ['CxSSxxa', [98, 2+padded.length/4, name.length, padded] ];
+       },
+
+       function(buf) {
+	   var res = buf.unpack('CCCC');
+           var ext = {};
+           ext.present = res[0];
+           ext.majorOpcode = res[1];
+           ext.firstEvent = res[2];
+           ext.firstError = res[3];
+           return ext;
+       }   
+
+   ],
+
    ListExtensions: [
        [ 'CxS', [99, 1] ],
 
@@ -297,6 +313,12 @@ module.exports = {
               var len = buf[off++];
               if (len == 0)
                   break;
+              if (off + len > buf.length)
+              {
+                  len = buf.length - off;
+                  if (len <= 0) 
+                     break;
+              }
               res.push(buf.unpackString(len, off));
               off += len;
           }
diff --git a/test/query_ext.js b/test/query_ext.js
new file mode 100644
index 0000000..52a539a
--- /dev/null
+++ b/test/query_ext.js
@@ -0,0 +1,17 @@
+var x11 = require('../lib/x11');
+var X = x11.createClient();
+var numExt = 0;
+X.on('connect', function(display) {
+    X.ListExtensions(function(list) {
+        console.log(list);
+        list.forEach(function(ext) {
+            numExt++;
+            X.QueryExtension(ext, function(e) {
+                e.name = ext;
+                console.log(e);
+                if (--numExt == 0)
+                    X.terminate();
+            });
+        });
+    });
+});