diff --git a/os_collect_config/config_drive.py b/os_collect_config/config_drive.py
index f64952b..3fcf23d 100644
--- a/os_collect_config/config_drive.py
+++ b/os_collect_config/config_drive.py
@@ -147,7 +147,7 @@ def all_block_devices():
     '''Run blkid and yield a BlockDevice for all devices.'''
     try:
         cmd = ['blkid', '-o', 'export']
-        out = subprocess.check_output(cmd)
+        out = subprocess.check_output(cmd, universal_newlines=True)
     except Exception as e:
         logger.error('Problem running "%s": %s', ' '.join(cmd), e)
     else:
diff --git a/tox.ini b/tox.ini
index 0964960..dd75919 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,7 +1,7 @@
 [tox]
 minversion = 2.0
 skipsdist = True
-envlist = py27,pep8
+envlist = py35,py27,pep8
 
 [testenv]
 usedevelop = True