Issue #1265 has been updated by Charlie Savage. Hi Usaku, I tried the same approach before submitting my patch, put it doesn't work: ruby test_dl2.rb: 1) Error: test_empty(DL::TestBase): DL::DLError: Invalid argument C:/Development/src/ruby_trunk/test/dl/test_base.rb:65:in `initialize' C:/Development/src/ruby_trunk/test/dl/test_base.rb:65:in `dlopen' C:/Development/src/ruby_trunk/test/dl/test_base.rb:65:in `setup' Not a very helpful error message, but it seems like you can't dynamically load msvcr90.dll (or if you can it doesn't work for me). Also, in your logic, instead of this: libc_so = libm_so = RbConfig::CONFIG["RUBY_SO_NAME"].split(/-/, 2)[0] + ".dll" Could you do this: libc_so = libm_so = RbConfig::CONFIG["sitearch"].split(/-/, 2)[1] + ".dll" Thanks, Charlie 1) Error: test_call_double(DL::TestDL): DL::DLError: unknown symbol "atof" test_dl2.rb:26:in `[]' test_dl2.rb:26:in `test_call_double' Etc.... The new code loads ruby19.dll. Is that what you mean to do? Or were you trying to ---------------------------------------- http://redmine.ruby-lang.org/issues/show/1265 ---------------------------------------- http://redmine.ruby-lang.org