Are below behaviors expected in JRuby?

CRuby

ruby 1.9.3p194 (2012-04-20) [i386-mingw32]

p 1.to_sym #=> in `<main>': undefined method `to_sym' for 1:Fixnum (NoMethodError)

JRuby

jruby --1.9

jruby 1.7.0.preview2 (1.9.3p203) 2012-08-07 4a6bb0a on Java HotSpot(TM) Client VM 1.6.0_29-b11 [Windows 7-x86]

p 1.to_sym #=> nil