Init.d script trouble shooting

I'm trying to run an init.d script when my rom boots to disable system services, and they aren't running. The script is as follows #!/system/bin/sh su -c pm disable com.google.android.gms/.update.SystemupdateService su -c pm disable com.google.android.gms/.update.SystemUpdateGcmTaskService I can confirm that normal pm disable commands work to disable non system applications. So I suspect I'm not doing something right to su privileges.