diff --git a/tuned/units/device_matcher.py b/tuned/units/device_matcher.py
index bc42718..03f3468 100644
--- a/tuned/units/device_matcher.py
+++ b/tuned/units/device_matcher.py
@@ -1,4 +1,5 @@
 import fnmatch
+import re
 
 class DeviceMatcher(object):
 	"""
@@ -16,7 +17,7 @@ class DeviceMatcher(object):
 		which matches all devices is added. The device matches if and only
 		if it matches some positive rule, but no negative rule.
 		"""
-		rules = rules_str.split()
+		rules = re.split(r"\s|,\s*", rules_str)
 		positive_rules = filter(lambda rule: not rule.startswith("!"), rules)
 		negative_rules = [rule[1:] for rule in rules if rule not in positive_rules]
 
diff --git a/tuned/units/manager.py b/tuned/units/manager.py
index bf22c23..78fe390 100644
--- a/tuned/units/manager.py
+++ b/tuned/units/manager.py
@@ -70,9 +70,7 @@ class Manager(object):
 			log.info("skipping unit '%s', all devices are already claimed by another unit" % unit_info.name)
 			return None
 
-		devices = []
-		for dev in unit_info.devices.split(","):
-			devices += self._device_matcher.match_list(str(dev).strip(), available_devices)
+		devices = self._device_matcher.match_list(unit_info.devices, available_devices)
 		if not devices:
 			log.info("skipping unit '%s', no matching devices available" % unit_info.name)
 			return None