diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 513b174..a5c721d 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,5 +1,6 @@
+repos:
 - repo: git://github.com/pre-commit/pre-commit-hooks
-  sha: 'v0.4.2'
+  rev: v1.2.3
   hooks:
     - id: check-added-large-files
     - id: check-docstring-first
diff --git a/.travis.yml b/.travis.yml
index 2b8fc1e..11164d7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,12 @@
 language: python
-env:
-- TOXENV=py27
-- TOXENV=py33
-- TOXENV=py34
+matrix:
+  include:
+    - python: 2.7
+      env: TOXENV=py27
+    - python: 3.5
+      env: TOXENV=py35
+    - python: 3.6
+      env: TOXENV=py36
 install:
 - pip install tox
 script:
diff --git a/debian/changelog b/debian/changelog
index 2ab3ecd..bcc54c6 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -6,7 +6,7 @@ docker-custodian (0.7.0) lucid; urgency=low
 
 docker-custodian (0.6.1) lucid; urgency=low
 
-  * New release for pypi 
+  * New release for pypi
 
  -- kwa <kwa@kwa-MacBookPro>  Wed, 31 Aug 2016 09:49:37 -0700
 
@@ -25,7 +25,7 @@ docker-custodian (0.5.3) lucid; urgency=low
 
 docker-custodian (0.5.2) lucid; urgency=low
 
-  * Fixed bug where never started containers that are not old were getting removed 
+  * Fixed bug where never started containers that are not old were getting removed
 
  -- Semir Patel <spatel@yelp.com>  Tue, 15 Dec 2015 09:44:26 -0800
 
@@ -58,7 +58,7 @@ docker-custodian (0.3.2) lucid; urgency=low
 
 docker-custodian (0.3.1) lucid; urgency=low
 
-  * Fix broken commands 
+  * Fix broken commands
 
  -- Daniel Nephin <dnephin@yelp.com>  Mon, 09 Mar 2015 17:58:03 -0700
 
diff --git a/docker_custodian/docker_gc.py b/docker_custodian/docker_gc.py
index cfcfa83..db7aba9 100644
--- a/docker_custodian/docker_gc.py
+++ b/docker_custodian/docker_gc.py
@@ -76,7 +76,7 @@ def get_all_images(client):
 
 def get_dangling_volumes(client):
     log.info("Getting dangling volumes")
-    volumes = client.volumes({'dangling': True})['Volumes']
+    volumes = client.volumes({'dangling': True})['Volumes'] or []
     log.info("Found %s dangling volumes", len(volumes))
     return volumes
 
diff --git a/tox.ini b/tox.ini
index 355c2b5..8713cf8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,py33,py34
+envlist = py27,py35,py36
 
 [testenv]
 deps =
@@ -9,5 +9,6 @@ deps =
     pytest
 commands =
     py.test {posargs:tests}
+    pre-commit autoupdate
     pre-commit install -f --install-hooks
     pre-commit run --all-files