diff --git a/slixmpp_omemo/__init__.py b/slixmpp_omemo/__init__.py
index 2e74900..b22ae49 100644
--- a/slixmpp_omemo/__init__.py
+++ b/slixmpp_omemo/__init__.py
@@ -144,7 +144,9 @@ class MissingOwnKey(XEP0384): pass
 class NoAvailableSession(XEP0384): pass
 
 
-class EncryptionPrepareException(XEP0384): pass
+class EncryptionPrepareException(XEP0384):
+    def __init__(self, errors):
+        self.errors = errors
 
 
 class UntrustedException(XEP0384):