diff --git a/modules/core/vault.py b/modules/core/vault.py
index 6505dc2..bd821be 100644
--- a/modules/core/vault.py
+++ b/modules/core/vault.py
@@ -1,6 +1,6 @@
 # pylint: disable=C0111,R0903
 
-"""Copy passwords from a password store into the clipboard (currently supports only "pass")
+"""Copy passwords from a password store into the clipboard (currently supports only 'pass')
 
 Many thanks to [@bbernhard](https://github.com/bbernhard) for the idea!
 
@@ -29,9 +29,9 @@ import bumblebee.engine
 def build_menu(parent, current_directory, callback):
     with os.scandir(current_directory) as it:
         for entry in it:
-            if entry.name.startswith("."): continue
+            if entry.name.startswith('.'): continue
             if entry.is_file():
-                name = entry.name[:entry.name.rfind(".")]
+                name = entry.name[:entry.name.rfind('.')]
                 parent.add_menuitem(name, callback=lambda : callback(os.path.join(current_directory, name)))
 
             else:
@@ -44,10 +44,10 @@ class Module(bumblebee.engine.Module):
         super(Module, self).__init__(engine, config,
             bumblebee.output.Widget(full_text=self.text)
         )
-        self._duration = int(self.parameter("duration", 30))
-        self._offx = int(self.parameter("offx", 0))
-        self._offy = int(self.parameter("offy", 0))
-        self._path = os.path.expanduser(self.parameter("location", "~/.password-store/"))
+        self._duration = int(self.parameter('duration', 30))
+        self._offx = int(self.parameter('offx', 0))
+        self._offy = int(self.parameter('offy', 0))
+        self._path = os.path.expanduser(self.parameter('location', '~/.password-store/'))
         self._reset()
         engine.input.register_callback(self, button=bumblebee.input.LEFT_MOUSE,
            cmd=self.popup)
@@ -60,14 +60,14 @@ class Module(bumblebee.engine.Module):
 
     def _reset(self):
         self._timer = None
-        self._text = str(self.parameter("text", "<click-for-password>"))
+        self._text = str(self.parameter('text', '<click-for-password>'))
 
     def _callback(self, secret_name):
-        secret_name = secret_name.replace(self._path, "") # remove common path
+        secret_name = secret_name.replace(self._path, '') # remove common path
         if self._timer:
             self._timer.cancel()
         # bumblebee.util.execute hangs for some reason
-        os.system("PASSWORD_STORE_CLIP_TIME={} pass -c {} > /dev/null 2>&1".format(self._duration, secret_name))
+        os.system('PASSWORD_STORE_CLIP_TIME={} pass -c {} > /dev/null 2>&1'.format(self._duration, secret_name))
         self._timer = threading.Timer(self._duration, self._reset)
         self._timer.start()
         self._start = int(time.time())
@@ -75,7 +75,7 @@ class Module(bumblebee.engine.Module):
 
     def text(self, widget):
         if self._timer:
-            return "{} ({}s)".format(self._text, self._duration - (int(time.time()) - self._start))
+            return '{} ({}s)'.format(self._text, self._duration - (int(time.time()) - self._start))
         return self._text
 
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4