diff --git a/buildscripts/osx.sh b/buildscripts/osx.sh
index 25c646b5..e58a49f4 100755
--- a/buildscripts/osx.sh
+++ b/buildscripts/osx.sh
@@ -16,7 +16,7 @@ echo "Creating OS X packages for Bitmessage."
 
 export PYBITMESSAGEVERSION=$1
 
-cd src && python3 build_osx.py py2app
+cd src && python2.7 build_osx.py py2app
 
 if [[ $? = "0" ]]; then
   hdiutil create -fs HFS+ -volname "Bitmessage" -srcfolder dist/Bitmessage.app dist/bitmessage-v$1.dmg
diff --git a/packages/systemd/bitmessage.service b/packages/systemd/bitmessage.service
index 66f04a7d..1a9f7f47 100644
--- a/packages/systemd/bitmessage.service
+++ b/packages/systemd/bitmessage.service
@@ -3,7 +3,7 @@ Description=Bitmessage Daemon
 After=network.target auditd.service
 
 [Service]
-ExecStart=/usr/bin/python3 /usr/src/PyBitmessage/src/bitmessagemain.py
+ExecStart=/usr/bin/python2 /usr/src/PyBitmessage/src/bitmessagemain.py
 ExecReload=/bin/kill -HUP $MAINPID
 KillMode=process
 Restart=on-failure
diff --git a/src/bitmessagecli.py b/src/bitmessagecli.py
index 10c8cd9b..84c618af 100644
--- a/src/bitmessagecli.py
+++ b/src/bitmessagecli.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python3
+#!/usr/bin/python2.7
 # -*- coding: utf-8 -*-
 # pylint: disable=too-many-lines,global-statement,too-many-branches,too-many-statements,inconsistent-return-statements
 # pylint: disable=too-many-nested-blocks,too-many-locals,protected-access,too-many-arguments,too-many-function-args
diff --git a/src/bitmessageqt/migrationwizard.py b/src/bitmessageqt/migrationwizard.py
index e51a0e69..4187ae85 100644
--- a/src/bitmessageqt/migrationwizard.py
+++ b/src/bitmessageqt/migrationwizard.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python2.7
 from PyQt6 import QtGui, QtWidgets
 
 
diff --git a/src/bitmessageqt/settingsmixin.py b/src/bitmessageqt/settingsmixin.py
index 836e0220..3cc8dc38 100644
--- a/src/bitmessageqt/settingsmixin.py
+++ b/src/bitmessageqt/settingsmixin.py
@@ -1,3 +1,4 @@
+#!/usr/bin/python2.7
 """
 src/settingsmixin.py
 ====================
diff --git a/src/build_osx.py b/src/build_osx.py
index 922680d2..d83e9b9b 100644
--- a/src/build_osx.py
+++ b/src/build_osx.py
@@ -1,7 +1,7 @@
 """Building osx."""
 import os
 from glob import glob
-from PyQt6 import QtCore
+from PyQt4 import QtCore
 from setuptools import setup
 
 name = "Bitmessage"
@@ -32,7 +32,7 @@ setup(
     setup_requires=["py2app"],
     options=dict(
         py2app=dict(
-            includes=['sip', 'PyQt6._qt'],
+            includes=['sip', 'PyQt4._qt'],
             iconfile="images/bitmessage.icns"
         )
     )
diff --git a/src/pybitmessage b/src/pybitmessage
index 46a8f75c..decebfff 100644
--- a/src/pybitmessage
+++ b/src/pybitmessage
@@ -1,4 +1,4 @@
-#!/usr/bin/python3
+#!/usr/bin/python2.7
 
 import os
 import pkg_resources