diff --git a/ci/requirements.txt b/ci/requirements.txt
index 81325bdf..a95201dc 100644
--- a/ci/requirements.txt
+++ b/ci/requirements.txt
@@ -6,3 +6,4 @@ jinja2
 lxml
 pylint
 sphinx
+pydbus
diff --git a/qubespolicy/agent.py b/qubespolicy/agent.py
index fa14b84e..e06c4681 100644
--- a/qubespolicy/agent.py
+++ b/qubespolicy/agent.py
@@ -23,13 +23,17 @@
 decisions.'''
 
 import pydbus
+# pylint: disable=import-error,wrong-import-position
 import gi
 gi.require_version('Gtk', '3.0')
 from gi.repository import GLib
+# pylint: enable=import-error
 
 import qubespolicy.rpcconfirmation
+# pylint: enable=wrong-import-position
 
 class PolicyAgent(object):
+    # pylint: disable=too-few-public-methods
     dbus = """
     <node>
       <interface name='org.qubesos.PolicyAgent'>
@@ -45,8 +49,10 @@ class PolicyAgent(object):
     </node>
     """
 
-    def Ask(self, source, service_name, targets, default_target,
+    @staticmethod
+    def Ask(source, service_name, targets, default_target,
             icons):
+        # pylint: disable=invalid-name
         entries_info = {}
         for target in targets:
             entries_info[target] = {}
diff --git a/qubespolicy/gtkhelpers.py b/qubespolicy/gtkhelpers.py
index f7d1e11e..1c546ba2 100644
--- a/qubespolicy/gtkhelpers.py
+++ b/qubespolicy/gtkhelpers.py
@@ -19,40 +19,36 @@
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #
 
-import gi
 import itertools
-
+# pylint: disable=import-error,wrong-import-position
+import gi
 gi.require_version('Gtk', '3.0')
 from gi.repository import Gtk, Gdk, GdkPixbuf, GObject, GLib
+# pylint: enable=import-error
+
 from qubespolicy.utils import sanitize_domain_name
+# pylint: enable=wrong-import-position
 
-
-class GtkIconGetter:
-    def __init__(self, size):
+class VMListModeler:
+    def __init__(self, domains_info=None):
+        self._entries = {}
+        self._domains_info = domains_info
         self._icons = {}
-        self._size = size
+        self._icon_size = 16
         self._theme = Gtk.IconTheme.get_default()
+        self._create_entries()
 
-    def get_icon(self, name):
+    def _get_icon(self, name):
         if name not in self._icons:
             try:
-                icon = self._theme.load_icon(name, self._size, 0)
-            except GLib.Error:
-                icon = self._theme.load_icon("edit-find", self._size, 0)
+                icon = self._theme.load_icon(name, self._icon_size, 0)
+            except GLib.Error:  # pylint: disable=catching-non-exception
+                icon = self._theme.load_icon("edit-find", self._icon_size, 0)
 
             self._icons[name] = icon
 
         return self._icons[name]
 
-
-class VMListModeler:
-    def __init__(self, domains_info=None):
-        self._icon_getter = GtkIconGetter(16)
-
-        self._entries = {}
-        self._domains_info = domains_info
-        self._create_entries()
-
     def _create_entries(self):
         for name, vm in self._domains_info.items():
             if name.startswith('$dispvm:'):
@@ -63,7 +59,7 @@ class VMListModeler:
                 dispvm = False
             sanitize_domain_name(vm_name, assert_sanitized=True)
 
-            icon = self._icon_getter.get_icon(vm.get('icon', None))
+            icon = self._get_icon(vm.get('icon', None))
 
             if dispvm:
                 display_name = 'Disposable VM ({})'.format(vm_name)
@@ -125,7 +121,7 @@ class VMListModeler:
             list_store = Gtk.ListStore(int, str, GdkPixbuf.Pixbuf)
 
             for entry_no, display_name in zip(itertools.count(),
-                    sorted(self._entries.keys())):
+                    sorted(self._entries)):
                 entry = self._entries[display_name]
                 if entry['api_name'] in vm_list:
                     list_store.append([entry_no, display_name, entry['icon']])
@@ -199,6 +195,7 @@ class VMListModeler:
 
 
 class GtkOneTimerHelper:
+    # pylint: disable=too-few-public-methods
     def __init__(self, wait_seconds):
         self._wait_seconds = wait_seconds
         self._current_timer_id = 0
diff --git a/qubespolicy/rpcconfirmation.py b/qubespolicy/rpcconfirmation.py
index 3001498e..50189276 100644
--- a/qubespolicy/rpcconfirmation.py
+++ b/qubespolicy/rpcconfirmation.py
@@ -18,15 +18,17 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #
-import pkg_resources
-from gi.repository import Gtk, Gdk, GLib
 import os
+from gi.repository import Gtk, Gdk, GLib  # pylint: disable=import-error
+import pkg_resources
+
 from qubespolicy.gtkhelpers import VMListModeler, FocusStealingHelper
 from qubespolicy.utils import sanitize_domain_name, \
     sanitize_service_name
 
 
 class RPCConfirmationWindow:
+    # pylint: disable=too-few-public-methods
     _source_file = pkg_resources.resource_filename('qubespolicy',
         os.path.join('glade', "RPCConfirmationWindow.glade"))
     _source_id = {'window': "RPCConfirmationWindow",
@@ -110,7 +112,8 @@ class RPCConfirmationWindow:
     def _can_perform_action(self):
         return self._focus_helper.can_perform_action()
 
-    def _escape_and_format_rpc_text(self, rpc_operation):
+    @staticmethod
+    def _escape_and_format_rpc_text(rpc_operation):
         escaped = GLib.markup_escape_text(rpc_operation)
 
         partitioned = escaped.partition('.')
@@ -161,7 +164,7 @@ class RPCConfirmationWindow:
                     self._escape_and_format_rpc_text(rpc_operation))
 
         self._entries_info = entries_info
-        list_modeler = self._new_VM_list_modeler()
+        list_modeler = self._new_vm_list_modeler()
 
         list_modeler.apply_model(self._rpc_combo_box, targets_list,
                     selection_trigger=self._update_ok_button_sensitivity,
@@ -186,7 +189,7 @@ class RPCConfirmationWindow:
 
         Gtk.main()
 
-    def _new_VM_list_modeler(self):
+    def _new_vm_list_modeler(self):
         return VMListModeler(self._entries_info)
 
     def _new_focus_stealing_helper(self):
@@ -209,4 +212,3 @@ def confirm_rpc(entries_info, source, rpc_operation, targets_list, target=None):
         targets_list, target)
 
     return window.confirm_rpc()
-
diff --git a/qubespolicy/tests/rpcconfirmation.py b/qubespolicy/tests/rpcconfirmation.py
index da28543a..fdff54f0 100755
--- a/qubespolicy/tests/rpcconfirmation.py
+++ b/qubespolicy/tests/rpcconfirmation.py
@@ -30,7 +30,7 @@ from qubespolicy.rpcconfirmation import RPCConfirmationWindow
 
 
 class MockRPCConfirmationWindow(RPCConfirmationWindow):
-    def _new_VM_list_modeler(self):
+    def _new_vm_list_modeler(self):
         return VMListModeler(mock_domains_info)
 
     def _new_focus_stealing_helper(self):
diff --git a/qubespolicy/utils.py b/qubespolicy/utils.py
index ac8ec18c..941f1f27 100644
--- a/qubespolicy/utils.py
+++ b/qubespolicy/utils.py
@@ -56,4 +56,3 @@ def sanitize_domain_name(input_string, assert_sanitized=False):
 
 def sanitize_service_name(input_string, assert_sanitized=False):
     return _sanitize_name(input_string, {'+'}, assert_sanitized)
-