Ctrl+P completion in `\eqref{}` using strings including `_` in `\label{}`

If `\label{abc_xyz}` is in a pandoc document, Ctrl+P in `\eqref{a}` after `a` can only leads to `\eqref{abc}` but not `\eqref{abc_xyz}`. Is there a way to let the completion know to search for the whole word in constructs like `\label{}`?
