diff --git a/Hermes/setup.py b/Hermes/setup.py
index 22dfc96283..10e1272e94 100644
--- a/Hermes/setup.py
+++ b/Hermes/setup.py
@@ -15,7 +15,7 @@
     'kazoo',
     'tornado',
     'psutil==5.6.3',
-    'attrs>=18.1.0',
+    'attrs>=18.1.0,<19.2.0',  # 19.2.0 removed "convert" attribute.
     'mock',
   ],
   test_suite='appscale.hermes',