diff --git a/tests/test_server.py b/tests/test_server.py
index b0ae993e..6a373b36 100644
--- a/tests/test_server.py
+++ b/tests/test_server.py
@@ -423,3 +423,8 @@ def test_start_background_task(self, eio):
         s.start_background_task('foo', 'bar', baz='baz')
         s.eio.start_background_task.assert_called_once_with('foo', 'bar',
                                                             baz='baz')
+
+    def test_sleep(self, eio):
+        s = server.Server()
+        s.sleep(1.23)
+        s.eio.sleep.assert_called_once_with(1.23)