diff --git a/setup.py b/setup.py
index 543a321d..e1d1729e 100644
--- a/setup.py
+++ b/setup.py
@@ -31,6 +31,7 @@ setup(
     install_requires=[
         'teal>=0.2.0a6',
         'marshmallow_enum',
+        'marshmallow==3.0.0b9'
         'ereuse-utils[Naming]>=0.4b1',
         'psycopg2-binary',
         'requests',