diff -r 6703ac68bf49 Lib/asyncio/tasks.py
--- a/Lib/asyncio/tasks.py	Fri Jul 31 23:36:00 2015 +0200
+++ b/Lib/asyncio/tasks.py	Sat Aug 01 02:09:33 2015 +0300
@@ -249,15 +249,21 @@
                     result._blocking = False
                     result.add_done_callback(self._wakeup)
                     self._fut_waiter = result
-                    if self._must_cancel:
-                        if self._fut_waiter.cancel():
-                            self._must_cancel = False
+                    if self._must_cancel and self._fut_waiter.cancel():
+                        self._must_cancel = False
                 else:
                     self._loop.call_soon(
                         self._step, None,
                         RuntimeError(
                             'yield was used instead of yield from '
                             'in task {!r} with {!r}'.format(self, result)))
+            elif isinstance(result, concurrent.futures.Future):
+                if self._must_cancel and self._fut_waiter.cancel():
+                    self._must_cancel = False
+                result.add_done_callback(
+                    functools.partial(
+                        self._loop.call_soon_threadsafe, self._wakeup))
+                self._fut_waiter = result
             elif result is None:
                 # Bare yield relinquishes control for one event loop iteration.
                 self._loop.call_soon(self._step)
diff -r 6703ac68bf49 Lib/concurrent/futures/_base.py
--- a/Lib/concurrent/futures/_base.py	Fri Jul 31 23:36:00 2015 +0200
+++ b/Lib/concurrent/futures/_base.py	Sat Aug 01 02:09:33 2015 +0300
@@ -315,6 +315,12 @@
                     hex(id(self)),
                    _STATE_TO_DESCRIPTION_MAP[self._state])
 
+    def __await__(self):
+        if not self.done():
+            yield self
+        assert self.done(), "yield from wasn't used with future"
+        return self.result()  # May raise too.
+
     def cancel(self):
         """Cancel the future if possible.