You can create it, you may want to include the default list of shells as well, from man shells (not directly, I copied it from another post elsewhere):

from man shells

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The following default shells are used by utilities:
/bin/bash, /bin/csh, /bin/jsh, /bin/ksh, /bin/pfcsh,
/bin/pfksh, /bin/pfsh, /bin/sh, /bin/tcsh, /bin/zsh,
/sbin/jsh, /sbin/sh, /usr/bin/bash, /usr/bin/csh,
/usr/bin/jsh, /usr/bin/ksh, /usr/bin/pfcsh, /usr/bin/pfksh,
/usr/bin/pfsh, and /usr/bin/sh, /usr/bin/tcsh, /usr/bin/zsh.
Note that /etc/shells overrides the default list.
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