diff --git a/toolkit/devtools/server/tests/unit/test_add_actors.js b/toolkit/devtools/server/tests/unit/test_add_actors.js
index 0ffc2c6d0bf..8fb1c634310 100644
--- a/toolkit/devtools/server/tests/unit/test_add_actors.js
+++ b/toolkit/devtools/server/tests/unit/test_add_actors.js
@@ -27,6 +27,7 @@ function run_test()
   add_test(test_pre_init_tab_actor);
   add_test(test_post_init_global_actor);
   add_test(test_post_init_tab_actor);
+  add_test(close_client);
   run_next_test();
 }
 
@@ -80,3 +81,7 @@ function test_post_init_tab_actor()
     }
   );
 }
+
+function close_client() {
+  gClient.close(() => run_next_test());
+}