diff --git a/.builtins.rb b/.builtins.rb
new file mode 100644
index 0000000..e42b8ac
--- /dev/null
+++ b/.builtins.rb
@@ -0,0 +1,4 @@
+# :stopdoc:
+class Array end
+class String end
+# :startdoc:
diff --git a/.document b/.document
index 5035202..bbe8ade 100644
--- a/.document
+++ b/.document
@@ -1,3 +1,4 @@
 LICENSE.txt
 README.md
+.builtins.rb
 lib/
diff --git a/lib/shellwords.rb b/lib/shellwords.rb
index 067432e..afd933a 100644
--- a/lib/shellwords.rb
+++ b/lib/shellwords.rb
@@ -68,6 +68,7 @@
 # 1: {IEEE Std 1003.1-2008, 2016 Edition, the Shell & Utilities volume}[http://pubs.opengroup.org/onlinepubs/9699919799/utilities/contents.html]
 
 module Shellwords
+  # The version number string.
   VERSION = "0.2.0"
 
   # Splits a string into an array of tokens in the same way the UNIX