diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5901e3f..7bb1c6c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,13 @@
 CHANGELOG
 =========
 
+v0.21c (February 1, 2017)
+-------------------------
+
+Installations and upgrades started failing about 10 days ago with the error "ImportError: No module named 'packaging'" after an upstream package (Python's setuptools) was updated by its maintainers. The updated package conflicted with Ubuntu 14.04's version of another package (Python's pip). This update upgrades both packages to remove the conflict.
+
+If you already encountered the error during installation or upgrade of Mail-in-a-Box, this update may not correct the problem on your existing system. See https://discourse.mailinabox.email/t/v0-21c-release-fixes-python-package-installation-issue/1881 for help if the problem persists after upgrading to this version of Mail-in-a-Box.
+
 v0.21b (December 4, 2016)
 -------------------------
 
diff --git a/README.md b/README.md
index 173a159..81d8952 100644
--- a/README.md
+++ b/README.md
@@ -59,7 +59,7 @@ by me:
 	$ curl -s https://keybase.io/joshdata/key.asc | gpg --import
 	gpg: key C10BDD81: public key "Joshua Tauberer <jt@occams.info>" imported
 
-	$ git verify-tag v0.21b
+	$ git verify-tag v0.21c
 	gpg: Signature made ..... using RSA key ID C10BDD81
 	gpg: Good signature from "Joshua Tauberer <jt@occams.info>"
 	gpg: WARNING: This key is not certified with a trusted signature!
@@ -72,7 +72,7 @@ and on my [personal homepage](https://razor.occams.info/). (Of course, if this r
 
 Checkout the tag corresponding to the most recent release:
 
-	$ git checkout v0.21b
+	$ git checkout v0.21c
 
 Begin the installation.
 
diff --git a/setup/bootstrap.sh b/setup/bootstrap.sh
index 51aa7af..25d59f5 100644
--- a/setup/bootstrap.sh
+++ b/setup/bootstrap.sh
@@ -7,7 +7,7 @@
 #########################################################
 
 if [ -z "$TAG" ]; then
-	TAG=v0.21b
+	TAG=v0.21c
 fi
 
 # Are we running as root?