diff --git a/Rakefile.rb b/Rakefile.rb
index e54d1cd..df128aa 100644
--- a/Rakefile.rb
+++ b/Rakefile.rb
@@ -7,18 +7,26 @@ require "rscons"
 NAME = "jes"
 GTEST_VERSION = "1.7.0"
 
+base_env = Rscons::Environment.new do |env|
+  env.build_root = "build"
+  env["CPPPATH"] << "src/lib/include"
+  env["CFLAGS"] += ["-Wall", "-O2"]
+  env["CXXFLAGS"] += ["-Wall", "-O2"]
+end
+
 task :library do
-  Rscons::Environment.new do |env|
-    env.build_root = "build"
-    env["CPPPATH"] << "src/lib/include"
+  base_env.clone(clone: :all) do |env|
     env.Library("^/lib#{NAME}.a", Dir["src/lib/**/*.{cc,c}"])
   end
 end
 
+task :gui => :library do
+  base_env.clone(clone: :all) do |env|
+  end
+end
+
 task :test => :library do
-  Rscons::Environment.new do |env|
-    env.build_root = "build"
-    env["CPPPATH"] << "src/lib/include"
+  base_env.clone(clone: :all) do |env|
     env["CPPPATH"] << "gtest-#{GTEST_VERSION}/include"
     env["CPPPATH"] << "gtest-#{GTEST_VERSION}"
     env["LIBS"] << NAME