diff --git a/Doc/reference/ldap.rst b/Doc/reference/ldap.rst
index d059dfa4..4d45d978 100644
--- a/Doc/reference/ldap.rst
+++ b/Doc/reference/ldap.rst
@@ -38,7 +38,8 @@ This module defines the following functions:
    The *uri* parameter may be a comma- or whitespace-separated list of URIs
    containing only the schema, the host, and the port fields. Note that
    when using multiple URIs you cannot determine to which URI your client
-   gets connected.
+   gets connected. If *uri* is :py:const:`None`, the default URIs from
+   ``ldap.conf`` or :py:const:`OPT_URI` global option will be used.
 
    If *fileno* parameter is given then the file descriptor will be used to
    connect to an LDAP server. The *fileno* must either be a socket file
diff --git a/Modules/functions.c b/Modules/functions.c
index f7d9cf37..9a977ff7 100644
--- a/Modules/functions.c
+++ b/Modules/functions.c
@@ -12,7 +12,7 @@ l_ldap_initialize(PyObject *unused, PyObject *args)
     int ret;
     PyThreadState *save;
 
-    if (!PyArg_ParseTuple(args, "s:initialize", &uri))
+    if (!PyArg_ParseTuple(args, "z:initialize", &uri))
         return NULL;
 
     save = PyEval_SaveThread();