diff --git a/requirements.txt b/requirements.txt
index 9ad9c02..8b70850 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 lxml >= 3.5.0, < 4
-zeep
+zeep >= 3.0, < 3.3
 nose
 mock
 coveralls