diff --git a/setup.cfg b/setup.cfg
index 82b6ed89b..24b1f0da9 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -48,7 +48,7 @@ scripts =
     tools/merge_metadata.py
     tools/parse_xsd2.py
 install_requires =
-    cryptography
+    cryptography >= 1.4
     defusedxml
     future
     pyOpenSSL