fix build on ruby2.2
fix build on ruby2.2

marshall-lee/eye,gitinsky/eye,kostya/eye,cuzic/eye,makevoid/eye,marshall-lee/eye,heyryanw/eye,esse/eye,SergXIIIth/eye,SergXIIIth/eye,heyryanw/eye,makevoid/eye,esse/eye,gitinsky/eye,kostya/eye,cuzic/eye