diff --git a/zcutil/make-release.py b/zcutil/make-release.py
index 5ca552402..1e081ff73 100755
--- a/zcutil/make-release.py
+++ b/zcutil/make-release.py
@@ -1,4 +1,4 @@
-#! /usr/bin/env python2
+#! /usr/bin/env python3
 
 import os
 import re
@@ -9,7 +9,7 @@ import subprocess
 import traceback
 import unittest
 import random
-from cStringIO import StringIO
+from io import StringIO
 from functools import wraps
 
 
@@ -77,6 +77,11 @@ def parse_args(args):
 
 # Top-level flow:
 def main_logged(release, releaseprev, releasefrom, releaseheight, hotfix):
+    verify_dependencies([
+        ('help2man', None),
+        ('debchange', 'devscripts'),
+    ])
+
     verify_tags(releaseprev, releasefrom)
     verify_version(release, releaseprev, hotfix)
     initialize_git(release, hotfix)
@@ -107,6 +112,20 @@ def phase(message):
     return deco
 
 
+@phase('Checking release script dependencies.')
+def verify_dependencies(dependencies):
+    for (dependency, pkg) in dependencies:
+        try:
+            sh_log(dependency, '--version')
+        except OSError:
+            raise SystemExit(
+                "Missing dependency {}{}".format(
+                    dependency,
+                    " (part of {} Debian package)".format(pkg) if pkg else "",
+                ),
+            )
+
+
 @phase('Checking tags.')
 def verify_tags(releaseprev, releasefrom):
     candidates = []
@@ -403,7 +422,7 @@ def initialize_logging():
 
 def sh_out(*args):
     logging.debug('Run (out): %r', args)
-    return subprocess.check_output(args)
+    return subprocess.check_output(args).decode()
 
 
 def sh_log(*args):
@@ -417,7 +436,7 @@ def sh_log(*args):
 
     logging.debug('Run (log PID %r): %r', p.pid, args)
     for line in p.stdout:
-        logging.debug('> %s', line.rstrip())
+        logging.debug('> %s', line.decode().rstrip())
     status = p.wait()
     if status != 0:
         raise SystemExit('Nonzero exit status: {!r}'.format(status))
@@ -443,6 +462,7 @@ def sh_progress(markers, *args):
     pbar.update(marker)
     logging.debug('Run (log PID %r): %r', p.pid, args)
     for line in p.stdout:
+        line = line.decode()
         logging.debug('> %s', line.rstrip())
         for idx, val in enumerate(markers[marker:]):
             if val in line:
@@ -557,6 +577,12 @@ class Version (object):
             self.hotfix,
         )
 
+    def __lt__(self, other):
+        return self._sort_tup() < other._sort_tup()
+
+    def __eq__(self, other):
+        return self._sort_tup() == other._sort_tup()
+
 
 class PathPatcher (object):
     def __init__(self, path):
diff --git a/zcutil/release-notes.py b/zcutil/release-notes.py
index 0fa9d1095..fdd23cf42 100755
--- a/zcutil/release-notes.py
+++ b/zcutil/release-notes.py
@@ -1,3 +1,4 @@
+#! /usr/bin/env python3
 # -*- coding: utf-8 -*-
 
 import re, os, os.path
@@ -110,7 +111,7 @@ def generate_release_note(version, prev, clear):
         latest_tag = subprocess.Popen(['git describe --abbrev=0'], shell=True, stdout=subprocess.PIPE).communicate()[0].strip()
     print("Previous release tag: ", latest_tag)
     notes = subprocess.Popen(['git shortlog --no-merges {0}..HEAD'.format(latest_tag)], shell=True, stdin=subprocess.PIPE, stdout=subprocess.PIPE).communicate()[0]
-    lines = notes.split('\n')
+    lines = notes.decode().split('\n')
     lines = [alias_authors_in_release_notes(line) for line in lines]
     temp_release_note = os.path.join(doc_dir, 'release-notes.md')
     with open(temp_release_note, 'r') as f: