diff --git a/guides/source/initialization.md b/guides/source/initialization.md
index 8fbb2346985dada05d9bc59c3689dd2b5c073e78..c0c8b7d4b62c3faa5b704bc7449839e82c1941a4 100644
--- a/guides/source/initialization.md
+++ b/guides/source/initialization.md
@@ -163,7 +163,7 @@ throwing an error message. If the command is valid, a method of the same name
 is called.
 
 ```ruby
-COMMAND_WHITELIST = %(plugin generate destroy console server dbconsole application runner new version help)
+COMMAND_WHITELIST = %w(plugin generate destroy console server dbconsole application runner new version help)
 
 def run_command!(command)
   command = parse_command(command)