--- a/Implab/PromiseExtensions.cs	Mon Feb 16 17:48:39 2015 +0300
+++ b/Implab/PromiseExtensions.cs	Tue Feb 17 18:16:26 2015 +0300
@@ -56,7 +56,7 @@
             Safe.ArgumentNotNull(that, "that");
             Safe.ArgumentNotNull(head, "head");
 
-            that.On(null,null,() => head.On(cleanup));
+            that.On(() => head.On(cleanup), PromiseEventType.Cancelled);
 
             return that;
         }
@@ -123,9 +123,9 @@
                                 new Exception("The dependency promise is failed", error)
                             );
                     },
-                    () => {
+                    reason => {
                         if (Interlocked.Increment(ref errors) == 1)
-                            medium.Reject(
+                            medium.Cancel(
                                 new Exception("The dependency promise is cancelled")
                             );
                     }
@@ -162,10 +162,10 @@
                                 new Exception("The dependency promise is failed", error)
                             );
                     },
-                    () => {
+                    reason => {
                         if (Interlocked.Increment(ref errors) == 1)
-                            medium.Reject(
-                                new Exception("The dependency promise is cancelled")
+                            medium.Cancel(
+                                new Exception("The dependency promise is cancelled", reason)
                             );
                     }
                 );
@@ -181,7 +181,7 @@
             Safe.ArgumentNotNull(that, "that");
             var tcs = new TaskCompletionSource<T>();
 
-            that.On(tcs.SetResult, tcs.SetException, tcs.SetCanceled);
+            that.On(tcs.SetResult, tcs.SetException, r => tcs.SetCanceled());
 
             return tcs.Task;
         }