diff --git a/Library/Homebrew/extend/string.rb b/Library/Homebrew/extend/string.rb
index 974906b1d2..ddc5fdf7ff 100644
--- a/Library/Homebrew/extend/string.rb
+++ b/Library/Homebrew/extend/string.rb
@@ -3,13 +3,3 @@ class String
     gsub /^.{#{slice(/^ +/).length}}/, ''
   end
 end
-
-if __FILE__ == $0
-  undented = <<-EOS.undent
-    hi
-....my friend over
-    there
-  EOS
-  
-  assert undented == "hi\nmy friend over\nthere\n"
-end
diff --git a/Library/Homebrew/test/test_string.rb b/Library/Homebrew/test/test_string.rb
new file mode 100644
index 0000000000..55a70f72c4
--- /dev/null
+++ b/Library/Homebrew/test/test_string.rb
@@ -0,0 +1,15 @@
+require 'testing_env'
+require 'utils'
+
+require 'extend/string'
+
+class StringTest <Test::Unit::TestCase
+  def test_undent
+    undented = <<-EOS.undent
+    hi
+....my friend over
+    there
+    EOS
+    assert undented == "hi\nmy friend over\nthere\n"
+  end
+end
diff --git a/Library/Homebrew/test/tests b/Library/Homebrew/test/tests
index 87125decb2..8d24ea435e 100755
--- a/Library/Homebrew/test/tests
+++ b/Library/Homebrew/test/tests
@@ -15,3 +15,4 @@
 /usr/bin/ruby test_ARGV.rb $*
 /usr/bin/ruby test_ENV.rb $*
 /usr/bin/ruby test_updater.rb $*
+/usr/bin/ruby test_string.rb $*