diff --git a/requirements.txt b/requirements.txt
index 6fe3090..20f335d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,7 @@
-# Requirements to build the charm
-charm-tools
+# This file is managed centrally.  If you find the need to modify this as a
+# one-off, please don't.  Intead, consult #openstack-charms and ask about
+# requirements management in charms via bot-control.  Thank you.
+#
+# Build requirements
+charm-tools>=2.4.4
 simplejson
-flake8
diff --git a/src/requirements.txt b/src/requirements.txt
deleted file mode 100644
index 28ecaca..0000000
--- a/src/requirements.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-flake8
-pytest
diff --git a/src/test-requirements.txt b/src/test-requirements.txt
index 16d0adb..f013863 100644
--- a/src/test-requirements.txt
+++ b/src/test-requirements.txt
@@ -1,19 +1,18 @@
-# The order of packages is significant, because pip processes them in the order
-# of appearance. Changing the order has an impact on the overall integration
-# process, which may cause wedges in the gate later.
+# This file is managed centrally.  If you find the need to modify this as a
+# one-off, please don't.  Intead, consult #openstack-charms and ask about
+# requirements management in charms via bot-control.  Thank you.
+charm-tools>=2.4.4
 coverage>=3.6
 mock>=1.2
 flake8>=2.2.4,<=2.4.1
 os-testr>=0.4.1
-charm-tools>=2.0.0
-requests==2.6.0
-# amulet deployment helpers
-git+https://github.com/juju/charm-helpers#egg=charmhelpers
+requests>=2.18.4
 # BEGIN: Amulet OpenStack Charm Helper Requirements
 # Liberty client lower constraints
-amulet>=1.14.3,<2.0
-bundletester>=0.6.1,<1.0
+amulet>=1.14.3,<2.0;python_version=='2.7'
+bundletester>=0.6.1,<1.0;python_version=='2.7'
 aodhclient>=0.1.0
+gnocchiclient>=3.1.0,<3.2.0
 python-barbicanclient>=4.0.1
 python-ceilometerclient>=1.5.0
 python-cinderclient>=1.4.0
@@ -28,6 +27,7 @@ python-openstackclient>=1.7.0
 python-swiftclient>=2.6.0
 pika>=0.10.0,<1.0
 distro-info
+git+https://github.com/juju/charm-helpers.git#egg=charmhelpers
 # END: Amulet OpenStack Charm Helper Requirements
-# NOTE: workaround for 14.04 pip/tox
-pytz
+pytz    # workaround for 14.04 pip/tox
+pyudev  # for ceph-* charm unit tests (not mocked?)
diff --git a/test-requirements.txt b/test-requirements.txt
index 9a0bed8..ca62003 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1,7 +1,13 @@
-# Unit test requirements
+# This file is managed centrally.  If you find the need to modify this as a
+# one-off, please don't.  Intead, consult #openstack-charms and ask about
+# requirements management in charms via bot-control.  Thank you.
+#
+# Lint and unit test requirements
 flake8>=2.2.4,<=2.4.1
 os-testr>=0.4.1
+requests>=2.18.4
 charms.reactive
 mock>=1.2
+nose>=1.3.7
 coverage>=3.6
-git+https://github.com/openstack/charms.openstack#egg=charms.openstack
+git+https://github.com/openstack/charms.openstack.git#egg=charms.openstack