diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index a26fd02..34fec68 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -50,12 +50,7 @@ module ActiveRecord
       socket   = config[:socket]
       username = config[:username] ? config[:username].to_s : 'root'
       password = config[:password].to_s
-
-      if config.has_key?(:database)
-        database = config[:database]
-      else
-        raise ArgumentError, "No database specified. Missing argument: database."
-      end
+		database = config[:database] # Not required, as cross-db joins are allowed in mysql
 
       # Require the MySQL driver and define Mysql::Result.all_hashes
       unless defined? Mysql