diff --git a/README.md b/README.md
index 60eda56..f2ecbcd 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,7 @@ Software required:
 * Python 2.5+
 * Twisted 8.0+
 * PyCrypto
+* pyasn1
 * Zope Interface
 
 See Wiki for some installation instructions.