diff --git a/polynum/base/backends.py b/polynum/base/backends.py
index 561c0b5..9364fd8 100644
--- a/polynum/base/backends.py
+++ b/polynum/base/backends.py
@@ -110,10 +110,13 @@ class CASBackend(PolynumBackendMixin, CASBackend):
             attributes = self.ldap_attributes_to_unicode(r[0][1])
             for key in attributes:
                 value = attributes[key][0]
-                setattr(user, key, value)
                 if key in self.USER_ATTRIBUTES:
+                    max_length = User._meta.get_field(self.USER_ATTRIBUTES[key]).max_length
+                    value = value[:max_length]
                     setattr(user, self.USER_ATTRIBUTES[key], value)
                 if key in self.PROFILE_ATTRIBUTES:
+                    max_length = PolynumProfile._meta.get_field(self.PROFILE_ATTRIBUTES[key]).max_length
+                    value = value[:max_length]
                     setattr(profile, self.PROFILE_ATTRIBUTES[key], value)
         profile.save()
         return user