irmin 0.9.9 Ezjsonm dependency wrong?

[dsheets]

https://travis-ci.org/mirage/ocaml-dns/jobs/84652266#L2126:

# File "lib/http/irmin_http_common.ml", line 202, characters 33-34
# Error: This expression has type Ezjsonm.t
#        but an expression was expected of type Ezjsonm.value
#        The first variant type does not allow tag(s)
#        `Bool, `Float, `Null, `String
# Command exited with code 2.