diff --git a/authentik/providers/saml/processors/assertion.py b/authentik/providers/saml/processors/assertion.py
index db6f46400..3391d16b4 100644
--- a/authentik/providers/saml/processors/assertion.py
+++ b/authentik/providers/saml/processors/assertion.py
@@ -157,7 +157,7 @@ class AssertionProcessor:
                     provider=self.provider,
                 )
                 if value is not None:
-                    name_id.text = value
+                    name_id.text = str(value)
                 return name_id
             except PropertyMappingExpressionException as exc:
                 Event.new(