diff --git a/bin/mpw-wallet b/bin/mpw-wallet
index e575c0d..bcc3fc2 100644
--- a/bin/mpw-wallet
+++ b/bin/mpw-wallet
@@ -66,7 +66,7 @@ cli    = MPW::Cli.new(config)
 
 cli.load_config
 
-if not options[:list].nil?
+if !options[:list].nil?
   cli.list_wallet
 else
   cli.get_wallet(options[:wallet])
diff --git a/lib/mpw/cli.rb b/lib/mpw/cli.rb
index 83b9af3..9571fec 100644
--- a/lib/mpw/cli.rb
+++ b/lib/mpw/cli.rb
@@ -103,7 +103,7 @@ class Cli
 
   # Request the GPG password and decrypt the file
   def decrypt
-    if not defined?(@mpw)
+    unless defined?(@mpw)
       @password = ask(I18n.t('display.gpg_password')) {|q| q.echo = false}
       @mpw      = MPW.new(@config.gpg_key, @wallet_file, @password, @config.gpg_exe)
     end
@@ -451,9 +451,7 @@ class Cli
       item    = get_item(items)
       confirm = ask("#{I18n.t('form.delete_item.ask')} (y/N) ").to_s
 
-      if not confirm =~ /^(y|yes|YES|Yes|Y)$/
-        return false
-      end
+      return false unless confirm =~ /^(y|yes|YES|Yes|Y)$/
 
       item.delete
       @mpw.write_data
@@ -516,7 +514,7 @@ class Cli
   # @args: file -> the import file
   def import(file)
     raise I18n.t('form.import.file_empty')     if file.to_s.empty?
-    raise I18n.t('form.import.file_not_exist') if not File.exist?(file)
+    raise I18n.t('form.import.file_not_exist') unless File.exist?(file)
 
     YAML::load_file(file).each_value do |row|
       item = Item.new(group:    row['group'],
@@ -530,8 +528,8 @@ class Cli
       next if item.empty?
 
       @mpw.add(item)
-      @mpw.set_password(item.id, row['password']) if not row['password'].to_s.empty?
-      @mpw.set_otp_key(item.id, row['otp_key'])   if not row['otp_key'].to_s.empty?
+      @mpw.set_password(item.id, row['password']) unless row['password'].to_s.empty?
+      @mpw.set_otp_key(item.id, row['otp_key'])   unless row['otp_key'].to_s.empty?
     end
 
     @mpw.write_data
diff --git a/lib/mpw/config.rb b/lib/mpw/config.rb
index 298ba61..8ec8e3a 100644
--- a/lib/mpw/config.rb
+++ b/lib/mpw/config.rb
@@ -73,7 +73,7 @@ class Config
       end
     end
 
-    if not gpg_key =~ /[a-zA-Z0-9.-_]+\@[a-zA-Z0-9]+\.[a-zA-Z]+/
+    unless gpg_key =~ /[a-zA-Z0-9.-_]+\@[a-zA-Z0-9]+\.[a-zA-Z]+/
       raise I18n.t('error.config.key_bad_format')
     end
 
diff --git a/lib/mpw/item.rb b/lib/mpw/item.rb
index 469af15..7c2547e 100644
--- a/lib/mpw/item.rb
+++ b/lib/mpw/item.rb
@@ -68,7 +68,7 @@ class Item
     @port      = options[:port].to_i  if options.has_key?(:port) and not options[:port].to_s.empty?
     @otp       = options[:otp]        if options.has_key?(:otp)
     @comment   = options[:comment]    if options.has_key?(:comment)
-    @last_edit = Time.now.to_i        if not options.has_key?(:no_update_last_edit)
+    @last_edit = Time.now.to_i        unless options.has_key?(:no_update_last_edit)
   end
 
   # Delete all data
diff --git a/lib/mpw/mpw.rb b/lib/mpw/mpw.rb
index 9147648..bb4e38b 100644
--- a/lib/mpw/mpw.rb
+++ b/lib/mpw/mpw.rb
@@ -33,7 +33,7 @@ class MPW
     @gpg_exe     = gpg_exe
     @wallet_file = wallet_file
 
-    if not @gpg_exe.to_s.empty?
+    unless @gpg_exe.to_s.empty?
       GPGME::Engine.set_info(GPGME::PROTOCOL_OpenPGP, @gpg_exe, "#{Dir.home}/.gnupg")
     end
   end
@@ -48,7 +48,7 @@ class MPW
 
     data       = nil
 
-    return if not File.exists?(@wallet_file)
+    return unless File.exists?(@wallet_file)
 
     Gem::Package::TarReader.new(File.open(@wallet_file)) do |tar|
       tar.each do |f|
@@ -80,7 +80,7 @@ class MPW
       end
     end
 
-    if not data.nil? and not data.empty?
+    unless data.to_s.empty?
       YAML.load(data).each_value do |d|
         @data.push(Item.new(id:        d['id'],
                             group:     d['group'],
@@ -254,14 +254,12 @@ class MPW
 
     @data.each do |item|
       next if item.empty?
-      next if not group.empty? and not group.eql?(item.group.to_s.downcase)
+      next unless group.empty? or group.eql?(item.group.to_s.downcase)
 
       host    = item.host.to_s.downcase
       comment = item.comment.to_s.downcase
 
-      if not host =~ /^.*#{search}.*$/ and not comment =~ /^.*#{search}.*$/
-        next
-      end
+      next unless host =~ /^.*#{search}.*$/ or comment =~ /^.*#{search}.*$/
 
       result.push(item)
     end
@@ -284,9 +282,7 @@ class MPW
   # args: id -> the item id
   #       key -> the new key
   def set_otp_key(id, key)
-    if not key.to_s.empty?
-      @otp_keys[id] = encrypt(key.to_s)
-    end
+    @otp_keys[id] = encrypt(key.to_s) unless key.to_s.empty?
   end
 
   # Get an opt key
@@ -305,7 +301,7 @@ class MPW
   # @args: id -> the item id
   # @rtrn: an otp code
   def get_otp_code(id)
-    if not @otp_keys.has_key?(id)
+    unless @otp_keys.has_key?(id)
       return 0
     else
       return ROTP::TOTP.new(decrypt(@otp_keys[id])).now
diff --git a/templates/add_form.erb b/templates/add_form.erb
index c2d6d73..bb81787 100644
--- a/templates/add_form.erb
+++ b/templates/add_form.erb
@@ -2,7 +2,7 @@
 host:           # <%= I18n.t('form.add_item.host') %>
 user:           # <%= I18n.t('form.add_item.login') %>
 group:          # <%= I18n.t('form.add_item.group') %> 
-protocol:       # <%= I18n.t('form.add_item.protocol') %><% if not password %>
+protocol:       # <%= I18n.t('form.add_item.protocol') %><% unless password %>
 password:       # <%= I18n.t('form.add_item.password') %><% end %>
 port:           # <%= I18n.t('form.add_item.port') %>
 comment:        # <%= I18n.t('form.add_item.comment') %>
diff --git a/templates/update_form.erb b/templates/update_form.erb
index e5363f8..f27da0b 100644
--- a/templates/update_form.erb
+++ b/templates/update_form.erb
@@ -2,7 +2,7 @@
 # <%= I18n.t('form.update_item.host') %>
 host: <%= item.host %>
 # <%= I18n.t('form.update_item.login') %>
-user: <%= item.user %><% if not password %>
+user: <%= item.user %><% unless password %>
 # <%= I18n.t('form.update_item.password') %>
 password: <% end %>
 # <%= I18n.t('form.update_item.group') %>