diff --git a/src/libstd/sys/unix/pipe.rs b/src/libstd/sys/unix/pipe.rs
index 1446600a77ed..33863d31437f 100644
--- a/src/libstd/sys/unix/pipe.rs
+++ b/src/libstd/sys/unix/pipe.rs
@@ -145,7 +145,7 @@ impl UnixStream {
             fd: self.fd(),
             guard: unsafe { self.inner.lock.lock().unwrap() },
         };
-        assert!(set_nonblocking(self.fd(), true).is_ok());
+        set_nonblocking(self.fd(), true);
         ret
     }