diff --git a/actix-rt/tests/tests.rs b/actix-rt/tests/tests.rs
index a49a033b..5fe1e894 100644
--- a/actix-rt/tests/tests.rs
+++ b/actix-rt/tests/tests.rs
@@ -217,8 +217,8 @@ fn system_stop_stops_arbiters() {
     System::current().stop();
     sys.run().unwrap();
 
-    // account for slightly slow thread de-spawns (only observed on windows)
-    thread::sleep(Duration::from_millis(100));
+    // account for slightly slow thread de-spawns
+    thread::sleep(Duration::from_millis(500));
 
     // arbiter should be dead and return false
     assert!(!Arbiter::current().spawn_fn(|| {}));