diff --git a/src/stream/stream/mod.rs b/src/stream/stream/mod.rs
index f6822d2..7fac00d 100644
--- a/src/stream/stream/mod.rs
+++ b/src/stream/stream/mod.rs
@@ -587,13 +587,13 @@ extension_trait! {
 
             assert_eq!(s.next().await, Some(1));
             // There will be no delay after the first time.
-            assert!(start.elapsed().as_millis() <= 210);
+            assert!(start.elapsed().as_millis() < 400);
 
             assert_eq!(s.next().await, Some(2));
-            assert!(start.elapsed().as_millis() <= 210);
+            assert!(start.elapsed().as_millis() < 400);
 
             assert_eq!(s.next().await, None);
-            assert!(start.elapsed().as_millis() <= 210);
+            assert!(start.elapsed().as_millis() < 400);
             #
             # }) }
             ```