diff --git a/src/saml2/config.py b/src/saml2/config.py
index 11ef785..83673ff 100644
--- a/src/saml2/config.py
+++ b/src/saml2/config.py
@@ -216,6 +216,7 @@ class Config(object):
         self.crypto_backend = 'xmlsec1'
         self.scope = ""
         self.allow_unknown_attributes = False
+        self.allow_unsolicited = False
         self.extension_schema = {}
         self.cert_handler_extra_class = None
         self.verify_encrypt_cert = None