Simple RMS question

I want to open a sequential file using RMS, append a single line and close it. It seemed to work but that was because I was using empty files to start or creating the file (FOP=CIF). When calling SYS$PUT I get the error %RMS-F-NEF which is not positioned to EOF on $PUT if the file is nonblank. Do I use SYS$FIND to position to EOF before the SYS$PUT?