diff --git a/src/libstd/sync/mpsc/mod.rs b/src/libstd/sync/mpsc/mod.rs
index 69ecd20106..7c8054e993 100644
--- a/src/libstd/sync/mpsc/mod.rs
+++ b/src/libstd/sync/mpsc/mod.rs
@@ -1418,6 +1418,10 @@ impl<T> Receiver<T> {
             if let Some(new_port) = port_or_empty {
                 unsafe {
                     mem::swap(self.inner_mut(), new_port.inner_mut());
+                    match self.inner() {
+                        Flavor::Shared(ref p) => { p.post_rx_upgrade(); }
+                        _ => {}
+                    }
                 }
             }

diff --git a/src/libstd/sync/mpsc/shared.rs b/src/libstd/sync/mpsc/shared.rs
index dbcdcdac93..401e791c67 100644
--- a/src/libstd/sync/mpsc/shared.rs
+++ b/src/libstd/sync/mpsc/shared.rs
@@ -387,6 +387,15 @@ impl<T> Packet<T> {
         }
     }

+    // Prepare for RX after an upgrade
+    pub fn post_rx_upgrade(&self) {
+        self.cnt.store(0, Ordering::SeqCst);
+        let ptr = self.to_wake.swap(0, Ordering::SeqCst);
+        if ptr!=0 {
+            let _token = unsafe{ SignalToken::cast_from_usize(ptr) };
+        }
+    }
+
     // Consumes ownership of the 'to_wake' field.
     fn take_to_wake(&self) -> SignalToken {
         let ptr = self.to_wake.load(Ordering::SeqCst);