cvs question

I just have a question about updating a package in CVS. From the example, I edit the spec file and it shows to type: make tag build. However this command fails, and doing make build doesnt seem to take the new spec file, I know I must be missing something simple here.. # make tag cvs tag -c dosemu-1_4_0-4_1905svn cvs tag: dosemu.spec is locally modified cvs [tag aborted]: correct the above errors first! make: *** [tag] Error 1