Vcaml does not build with OCaml 5.1

Build error looks like this

=== ERROR while compiling vcaml.v0.16.0 ======================================#
context 2.2.1 | linux/x86_64 | ocaml-base-compiler.5.1.1 | https://opam.ocaml.org#4a9170ea6d035edaf46f2af0545ca66d06561668
path ~/place/vvvcaml/_opam/.opam-switch/build/vcaml.v0.16.0
command ~/.opam/opam-init/hooks/sandbox.sh build dune build -p vcaml -j 7
exit-code 1
env-file ~/.opam/log/vcaml-794317-262fd9.env
output-file ~/.opam/log/vcaml-794317-262fd9.out
## output ###
[...]
113 | end)
114 | (Open_on_rhs_intf)
115 | ()
Error: The functor application is ill-typed.
These arguments:
$S1 Open_on_rhs_intf ()
do not match these parameters:
functor (X : Base__Applicative_intf.For_let_syntax) (Intf : ...)
(Impl : Intf.S) -> ...
1. Module $S1 matches the expected module type Base__Applicative_intf.For_let_syntax
2. Module Open_on_rhs_intf matches the expected module type
3. The functor was expected to be applicative at this position