diff --git a/docs/x509.rst b/docs/x509.rst
index 96255a2..a40727c 100644
--- a/docs/x509.rst
+++ b/docs/x509.rst
@@ -959,13 +959,13 @@
 
     .. attribute:: organization
 
-        :type: :term:`text` or None
+        :type: :term:`text`
 
     .. attribute:: notice_numbers
 
-        :type: list or None
+        :type: list
 
-        A list of integers or None.
+        A list of integers.
 
 Object Identifiers
 ~~~~~~~~~~~~~~~~~~