diff --git a/src/stream/interval.rs b/src/stream/interval.rs
index 0161240..fe249fb 100644
--- a/src/stream/interval.rs
+++ b/src/stream/interval.rs
@@ -72,7 +72,7 @@ impl Stream for Interval {
             return Poll::Pending;
         }
         let interval = self.interval;
-        std::mem::replace(&mut self.delay, Timer::after(interval));
+        let _ = std::mem::replace(&mut self.delay, Timer::after(interval));
         Poll::Ready(Some(()))
     }
 }
diff --git a/src/stream/stream/throttle.rs b/src/stream/stream/throttle.rs
index 15a0f31..4d4cc87 100644
--- a/src/stream/stream/throttle.rs
+++ b/src/stream/stream/throttle.rs
@@ -59,7 +59,7 @@ impl<S: Stream> Stream for Throttle<S> {
             Poll::Ready(None) => Poll::Ready(None),
             Poll::Ready(Some(v)) => {
                 *this.blocked = true;
-                std::mem::replace(&mut *this.delay, Timer::after(*this.duration));
+                let _ = std::mem::replace(&mut *this.delay, Timer::after(*this.duration));
                 Poll::Ready(Some(v))
             }
         }