diff --git a/packstack/installer/utils/network.py b/packstack/installer/utils/network.py
index 22c2aa5a3..0d12b8bcc 100644
--- a/packstack/installer/utils/network.py
+++ b/packstack/installer/utils/network.py
@@ -24,7 +24,7 @@ def get_localhost_ip():
             nsrvs.append(match.group('ns_ip'))
 
     # try to connect to nameservers and return own IP address
-    nsrvs.append('8.8.8.8') # default to google dns
+    nsrvs.append('8.8.8.8')  # default to google dns
     for i in nsrvs:
         try:
             s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
diff --git a/packstack/installer/utils/shell.py b/packstack/installer/utils/shell.py
index 787a7f496..7bf6fc97e 100644
--- a/packstack/installer/utils/shell.py
+++ b/packstack/installer/utils/shell.py
@@ -18,9 +18,9 @@ def execute(cmd, workdir=None, can_fail=False, mask_list=None,
     code. Otherwise
     """
     mask_list = mask_list or []
-    repl_list = [("'","'\\''")]
+    repl_list = [("'", "'\\''")]
 
-    if type(cmd) is not types.StringType:
+    if not isinstance(cmd, types.StringType):
         import pipes
         masked = ' '.join((pipes.quote(i) for i in cmd))
     else:
@@ -58,7 +58,7 @@ class ScriptRunner(object):
     def execute(self, logerrors=True, maskList=None):
         maskList = maskList or []
         script = "\n".join(self.script)
-        logging.debug("# ============ ssh : %r =========="%self.ip)
+        logging.debug("# ============ ssh : %r ==========" % self.ip)
 
         _PIPE = subprocess.PIPE  # pylint: disable=E1101
         if self.ip:
@@ -71,7 +71,7 @@ class ScriptRunner(object):
                                stderr=_PIPE, close_fds=True,
                                shell=False)
 
-        replace_list = [("'","'\\''")]
+        replace_list = [("'", "'\\''")]
         logging.debug(mask_string(script, maskList, replace_list))
         script = "function t(){ exit $? ; } \n trap t ERR \n" + script
         stdoutdata, stderrdata = obj.communicate(script)
diff --git a/tox.ini b/tox.ini
index f8c66fcce..2b2916823 100644
--- a/tox.ini
+++ b/tox.ini
@@ -18,7 +18,9 @@ downloadcache = ~/cache/pip
 [testenv:pep8]
 deps=pep8==1.2
 commands = pep8 --exclude=*.pyc --repeat --show-source \
-           packstack/modules tests setup.py
+           packstack/modules tests setup.py packstack/installer/utils \
+           packstack/installer/processors.py
+
 
 [testenv:cover]
 setenv = NOSE_WITH_COVERAGE=1