diff --git a/saml_utils.py b/saml_utils.py
index 4870b07..cf3db8d 100644
--- a/saml_utils.py
+++ b/saml_utils.py
@@ -33,7 +33,7 @@ def prepare_flask_request(request):
         'script_name': request.path,
         'get_data': request.args.copy(),
         # Uncomment if using ADFS as IdP, https://github.com/onelogin/python-saml/pull/144
-        # 'lowercase_urlencoding': True,
+        'lowercase_urlencoding': True,
         'post_data': request.form.copy()
     }