diff --git a/setup.py b/setup.py
index f50c4d86..5094497c 100755
--- a/setup.py
+++ b/setup.py
@@ -88,8 +88,8 @@ setup(name='fdroidserver',
           'paramiko',
           'Pillow',
           'apache-libcloud >= 0.14.1',
-          'pyasn1',
-          'pyasn1-modules',
+          'pyasn1 <0.5.0, >=0.4.1',
+          'pyasn1-modules == 0.2.1',
           'python-vagrant',
           'PyYAML',
           'qrcode',