diff --git a/semaphore/semaphore.go b/semaphore/semaphore.go
index 7f096fe..30f632c 100644
--- a/semaphore/semaphore.go
+++ b/semaphore/semaphore.go
@@ -67,7 +67,12 @@ func (s *Weighted) Acquire(ctx context.Context, n int64) error {
 			// fix up the queue, just pretend we didn't notice the cancelation.
 			err = nil
 		default:
+			isFront := s.waiters.Front() == elem
 			s.waiters.Remove(elem)
+			// If we're at the front and there're extra tokens left, notify other waiters.
+			if isFront && s.size > s.cur {
+				s.notifyWaiters()
+			}
 		}
 		s.mu.Unlock()
 		return err
@@ -97,6 +102,11 @@ func (s *Weighted) Release(n int64) {
 		s.mu.Unlock()
 		panic("semaphore: released more than held")
 	}
+	s.notifyWaiters()
+	s.mu.Unlock()
+}
+
+func (s *Weighted) notifyWaiters() {
 	for {
 		next := s.waiters.Front()
 		if next == nil {
@@ -123,5 +133,4 @@ func (s *Weighted) Release(n int64) {
 		s.waiters.Remove(next)
 		close(w.ready)
 	}
-	s.mu.Unlock()
 }
diff --git a/semaphore/semaphore_test.go b/semaphore/semaphore_test.go
index b5f8f13..6e8eca2 100644
--- a/semaphore/semaphore_test.go
+++ b/semaphore/semaphore_test.go
@@ -169,3 +169,34 @@ func TestLargeAcquireDoesntStarve(t *testing.T) {
 	sem.Release(n)
 	wg.Wait()
 }
+
+// translated from https://github.com/zhiqiangxu/util/blob/master/mutex/crwmutex_test.go#L43
+func TestAllocCancelDoesntStarve(t *testing.T) {
+	sem := semaphore.NewWeighted(10)
+
+	// Block off a portion of the semaphore so that Acquire(_, 10) can eventually succeed.
+	sem.Acquire(context.Background(), 1)
+
+	// In the background, Acquire(_, 10).
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	go func() {
+		sem.Acquire(ctx, 10)
+	}()
+
+	// Wait until the Acquire(_, 10) call blocks.
+	for sem.TryAcquire(1) {
+		sem.Release(1)
+		runtime.Gosched()
+	}
+
+	// Now try to grab a read lock, and simultaneously unblock the Acquire(_, 10) call.
+	// Both Acquire calls should unblock and return, in either order.
+	go cancel()
+
+	err := sem.Acquire(context.Background(), 1)
+	if err != nil {
+		t.Fatalf("Acquire(_, 1) failed unexpectedly: %v", err)
+	}
+	sem.Release(1)
+}