diff --git a/futures-util/src/stream/futures_unordered/iter.rs b/futures-util/src/stream/futures_unordered/iter.rs
index 04db5ee753..20248c70fe 100644
--- a/futures-util/src/stream/futures_unordered/iter.rs
+++ b/futures-util/src/stream/futures_unordered/iter.rs
@@ -2,6 +2,7 @@ use super::task::Task;
 use super::FuturesUnordered;
 use core::marker::PhantomData;
 use core::pin::Pin;
+use core::ptr;
 use core::sync::atomic::Ordering::Relaxed;
 
 /// Mutable iterator over all futures in the unordered set.
@@ -58,6 +59,9 @@ impl<Fut: Unpin> Iterator for IntoIter<Fut> {
             // valid `next_all` checks can be skipped.
             let next = (**task).next_all.load(Relaxed);
             *task = next;
+            if !task.is_null() {
+                *(**task).prev_all.get() = ptr::null_mut();
+            }
             self.len -= 1;
             Some(future)
         }
diff --git a/futures/tests/stream_futures_unordered.rs b/futures/tests/stream_futures_unordered.rs
index f62f733610..398170a7cf 100644
--- a/futures/tests/stream_futures_unordered.rs
+++ b/futures/tests/stream_futures_unordered.rs
@@ -261,6 +261,20 @@ fn into_iter_len() {
     assert!(into_iter.next().is_none());
 }
 
+#[test]
+fn into_iter_partial() {
+    let stream = vec![future::ready(1), future::ready(2), future::ready(3), future::ready(4)]
+        .into_iter()
+        .collect::<FuturesUnordered<_>>();
+
+    let mut into_iter = stream.into_iter();
+    assert!(into_iter.next().is_some());
+    assert!(into_iter.next().is_some());
+    assert!(into_iter.next().is_some());
+    assert_eq!(into_iter.len(), 1);
+    // don't panic when iterator is dropped before completing
+}
+
 #[test]
 fn futures_not_moved_after_poll() {
     // Future that will be ready after being polled twice,