diff --git a/deploy-cluster-aws/clusterize_confiles.py b/deploy-cluster-aws/clusterize_confiles.py
index 498953e5..d1fcb6ee 100644
--- a/deploy-cluster-aws/clusterize_confiles.py
+++ b/deploy-cluster-aws/clusterize_confiles.py
@@ -1,58 +1,95 @@
 # -*- coding: utf-8 -*-
 """Given a directory full of default BigchainDB config files,
 transform them into config files for a cluster with proper
-keyrings, API endpoint values, etc.
+keyrings, API endpoint values, etc. This script is meant to
+be interpreted as a Python 2 script.
 
-Note: This script assumes that there is a file named hostlist.py
+Note 1: This script assumes that there is a file named hostlist.py
 containing public_dns_names = a list of the public DNS names of
 all the hosts in the cluster.
 
+Note 2: If the optional -k argument is included, then a keypairs.py
+file must exist and must have enough keypairs in it to assign one
+to each of the config files in the directory of config files.
+You can create a keypairs.py file using write_keypairs_file.py
+
 Usage:
-    python clusterize_confiles.py <dir> <number_of_files>
+    python clusterize_confiles.py [-h] [-k] dir number_of_files
 """
 
 from __future__ import unicode_literals
+
 import os
 import json
 import argparse
 
 from hostlist import public_dns_names
 
+if os.path.isfile('keypairs.py'):
+    from keypairs import keypairs_list
+
 
 # Parse the command-line arguments
-parser = argparse.ArgumentParser()
+desc = 'Transform a directory of default BigchainDB config files '
+desc += 'into config files for a cluster'
+parser = argparse.ArgumentParser(description=desc)
 parser.add_argument('dir',
                     help='Directory containing the config files')
 parser.add_argument('number_of_files',
                     help='Number of config files expected in dir',
                     type=int)
+parser.add_argument('-k', '--use-keypairs',
+                    action='store_true',
+                    default=False,
+                    help='Use public and private keys from keypairs.py')
 args = parser.parse_args()
 
 conf_dir = args.dir
-numfiles_expected = int(args.number_of_files)
+num_files_expected = int(args.number_of_files)
+use_keypairs = args.use_keypairs
 
 # Check if the number of files in conf_dir is what was expected
-conf_files = os.listdir(conf_dir)
-numfiles = len(conf_files)
-if numfiles != numfiles_expected:
+conf_files = sorted(os.listdir(conf_dir))
+num_files = len(conf_files)
+if num_files != num_files_expected:
     raise ValueError('There are {} files in {} but {} were expected'.
-                     format(numfiles, conf_dir, numfiles_expected))
+                     format(num_files, conf_dir, num_files_expected))
 
-# Make a list containing all the public keys from
-# all the config files
-pubkeys = []
-for filename in conf_files:
-    file_path = os.path.join(conf_dir, filename)
-    with open(file_path, 'r') as f:
-        conf_dict = json.load(f)
-        pubkey = conf_dict['keypair']['public']
-        pubkeys.append(pubkey)
+# If the -k option was included, check to make sure there are enough keypairs
+# in keypairs_list
+num_keypairs = len(keypairs_list)
+if use_keypairs:
+    if num_keypairs < num_files:
+        raise ValueError('There are {} config files in {} but '
+                         'there are only {} keypairs in keypairs.py'.
+                         format(num_files, conf_dir, num_keypairs))
+
+# Make a list containing all the public keys
+if use_keypairs:
+    print('Using keypairs from keypairs.py')
+    pubkeys = [keypair[1] for keypair in keypairs_list]
+else:
+    # read the pubkeys from the config files in conf_dir
+    pubkeys = []
+    for filename in conf_files:
+        file_path = os.path.join(conf_dir, filename)
+        with open(file_path, 'r') as f:
+            conf_dict = json.load(f)
+            pubkey = conf_dict['keypair']['public']
+            pubkeys.append(pubkey)
 
 # Rewrite each config file, one at a time
 for i, filename in enumerate(conf_files):
     file_path = os.path.join(conf_dir, filename)
     with open(file_path, 'r') as f:
         conf_dict = json.load(f)
+        # If the -k option was included
+        # then replace the private and public keys
+        # with those from keypairs_list
+        if use_keypairs:
+            keypair = keypairs_list[i]
+            conf_dict['keypair']['private'] = keypair[0]
+            conf_dict['keypair']['public'] = keypair[1]
         # The keyring is the list of *all* public keys
         # minus the config file's own public key
         keyring = list(pubkeys)
@@ -64,8 +101,10 @@ for i, filename in enumerate(conf_files):
         # Set the api_endpoint
         conf_dict['api_endpoint'] = 'http://' + public_dns_names[i] + \
                                     ':9984/api/v1'
+
     # Delete the config file
     os.remove(file_path)
+
     # Write new config file with the same filename
     print('Rewriting {}'.format(file_path))
     with open(file_path, 'w') as f2: