diff --git a/lib/xgrep/rails_env.rb b/lib/xgrep/rails_env.rb
index e0df1e0..6174f07 100644
--- a/lib/xgrep/rails_env.rb
+++ b/lib/xgrep/rails_env.rb
@@ -7,6 +7,27 @@ module Xgrep
     end
 
     def update_pathspec ( pathspec )
+      files = %w{Capfile Gemfile Rakefile}
+      dirs  = %w{app config db lib}
+      specs = %w{spec}
+
+      if pathspec.empty?
+        @pathspec = files + dirs + specs
+      elsif pathspec.include? :core
+        @pathspec = files + dirs
+      else
+        @pathspec += %w{app/assets}      if pathspec.include? :asset
+        @pathspec += %w{app/helpers}     if pathspec.include? :helper
+        @pathspec += %w{app/mailers}     if pathspec.include? :mailer
+        @pathspec += %w{app/models}      if pathspec.include? :models
+        @pathspec += %w{app/views}       if pathspec.include? :views
+        @pathspec += %w{app/controllers} if pathspec.include? :controllers
+        @pathspec += %w{app/services}    if pathspec.include? :services
+        @pathspec += %w{config}          if pathspec.include? :config
+        @pathspec += %w{db}              if pathspec.include? :db
+        @pathspec += %w{lib}             if pathspec.include? :lib
+        @pathspec += %w{spec}            if pathspec.include? :spec
+      end
     end
   end
 end