diff --git a/acme/setup.py b/acme/setup.py
index 3ac2271a8..6d3dcdf84 100644
--- a/acme/setup.py
+++ b/acme/setup.py
@@ -3,7 +3,7 @@ from setuptools import find_packages
 from setuptools.command.test import test as TestCommand
 import sys
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Please update tox.ini when modifying dependency version requirements
 install_requires = [
diff --git a/certbot-apache/setup.py b/certbot-apache/setup.py
index e4fa92a3c..5895ec810 100644
--- a/certbot-apache/setup.py
+++ b/certbot-apache/setup.py
@@ -4,7 +4,7 @@ from setuptools.command.test import test as TestCommand
 import sys
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
diff --git a/certbot-compatibility-test/setup.py b/certbot-compatibility-test/setup.py
index 063f9d1aa..40cde4352 100644
--- a/certbot-compatibility-test/setup.py
+++ b/certbot-compatibility-test/setup.py
@@ -4,7 +4,7 @@ from setuptools import setup
 from setuptools import find_packages
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 install_requires = [
     'certbot',
diff --git a/certbot-dns-cloudflare/setup.py b/certbot-dns-cloudflare/setup.py
index f56169196..6b72d0a76 100644
--- a/certbot-dns-cloudflare/setup.py
+++ b/certbot-dns-cloudflare/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup
 from setuptools import find_packages
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
diff --git a/certbot-dns-cloudxns/setup.py b/certbot-dns-cloudxns/setup.py
index 3e677bfce..4c58d56d0 100644
--- a/certbot-dns-cloudxns/setup.py
+++ b/certbot-dns-cloudxns/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup
 from setuptools import find_packages
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
diff --git a/certbot-dns-digitalocean/setup.py b/certbot-dns-digitalocean/setup.py
index 561e8b72b..4dabc207f 100644
--- a/certbot-dns-digitalocean/setup.py
+++ b/certbot-dns-digitalocean/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup
 from setuptools import find_packages
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
diff --git a/certbot-dns-dnsimple/setup.py b/certbot-dns-dnsimple/setup.py
index 88bc0f243..20ed5457d 100644
--- a/certbot-dns-dnsimple/setup.py
+++ b/certbot-dns-dnsimple/setup.py
@@ -3,7 +3,7 @@ from setuptools import setup
 from setuptools import find_packages
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
diff --git a/certbot-dns-dnsmadeeasy/setup.py b/certbot-dns-dnsmadeeasy/setup.py
index 84577d85e..85dcaafa3 100644
--- a/certbot-dns-dnsmadeeasy/setup.py
+++ b/certbot-dns-dnsmadeeasy/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup
 from setuptools import find_packages
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
diff --git a/certbot-dns-gehirn/setup.py b/certbot-dns-gehirn/setup.py
index b7fa4bfb6..f020354dc 100644
--- a/certbot-dns-gehirn/setup.py
+++ b/certbot-dns-gehirn/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup
 from setuptools import find_packages
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Please update tox.ini when modifying dependency version requirements
 install_requires = [
diff --git a/certbot-dns-google/setup.py b/certbot-dns-google/setup.py
index a2f636d77..61d365189 100644
--- a/certbot-dns-google/setup.py
+++ b/certbot-dns-google/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup
 from setuptools import find_packages
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
diff --git a/certbot-dns-linode/setup.py b/certbot-dns-linode/setup.py
index b9e025a6c..807e9b889 100644
--- a/certbot-dns-linode/setup.py
+++ b/certbot-dns-linode/setup.py
@@ -1,7 +1,7 @@
 from setuptools import setup
 from setuptools import find_packages
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Please update tox.ini when modifying dependency version requirements
 install_requires = [
diff --git a/certbot-dns-luadns/setup.py b/certbot-dns-luadns/setup.py
index 692fae164..3ee8fb2fe 100644
--- a/certbot-dns-luadns/setup.py
+++ b/certbot-dns-luadns/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup
 from setuptools import find_packages
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
diff --git a/certbot-dns-nsone/setup.py b/certbot-dns-nsone/setup.py
index 4ec01e8d6..2cc44406f 100644
--- a/certbot-dns-nsone/setup.py
+++ b/certbot-dns-nsone/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup
 from setuptools import find_packages
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
diff --git a/certbot-dns-ovh/setup.py b/certbot-dns-ovh/setup.py
index a18ee280e..b3abce754 100644
--- a/certbot-dns-ovh/setup.py
+++ b/certbot-dns-ovh/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup
 from setuptools import find_packages
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
diff --git a/certbot-dns-rfc2136/setup.py b/certbot-dns-rfc2136/setup.py
index 0daf434f0..0da7cc98a 100644
--- a/certbot-dns-rfc2136/setup.py
+++ b/certbot-dns-rfc2136/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup
 from setuptools import find_packages
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
diff --git a/certbot-dns-route53/setup.py b/certbot-dns-route53/setup.py
index c1974c470..548a567b4 100644
--- a/certbot-dns-route53/setup.py
+++ b/certbot-dns-route53/setup.py
@@ -1,7 +1,7 @@
 from setuptools import setup
 from setuptools import find_packages
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
diff --git a/certbot-dns-sakuracloud/setup.py b/certbot-dns-sakuracloud/setup.py
index fe999b996..7c5bfe7f3 100644
--- a/certbot-dns-sakuracloud/setup.py
+++ b/certbot-dns-sakuracloud/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup
 from setuptools import find_packages
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Please update tox.ini when modifying dependency version requirements
 install_requires = [
diff --git a/certbot-nginx/setup.py b/certbot-nginx/setup.py
index cc2b4317d..f3f0b6640 100644
--- a/certbot-nginx/setup.py
+++ b/certbot-nginx/setup.py
@@ -4,7 +4,7 @@ from setuptools.command.test import test as TestCommand
 import sys
 
 
-version = '0.40.1'
+version = '1.0.0.dev0'
 
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
diff --git a/certbot/__init__.py b/certbot/__init__.py
index d3ca008a0..30b52be1a 100644
--- a/certbot/__init__.py
+++ b/certbot/__init__.py
@@ -1,4 +1,4 @@
 """Certbot client."""
 
 # version number like 1.2.3a0, must have at least 2 parts, like 1.2
-__version__ = '0.40.1'
+__version__ = '1.0.0.dev0'
diff --git a/letsencrypt-auto-source/letsencrypt-auto b/letsencrypt-auto-source/letsencrypt-auto
index 9f3d2af08..386d19531 100755
--- a/letsencrypt-auto-source/letsencrypt-auto
+++ b/letsencrypt-auto-source/letsencrypt-auto
@@ -31,7 +31,7 @@ if [ -z "$VENV_PATH" ]; then
 fi
 VENV_BIN="$VENV_PATH/bin"
 BOOTSTRAP_VERSION_PATH="$VENV_PATH/certbot-auto-bootstrap-version.txt"
-LE_AUTO_VERSION="0.40.1"
+LE_AUTO_VERSION="1.0.0.dev0"
 BASENAME=$(basename $0)
 USAGE="Usage: $BASENAME [OPTIONS]
 A self-updating wrapper script for the Certbot ACME client. When run, updates