query with option returns substring in some cases

MWE

julia> d = Dict("type"=>"bugner_gaussian")
Dict{String, String} with 1 entry:
  "type" => "bugner_gaussian"

julia> query(String, d, "type")
"bugner_gaussian"

julia> query(String, d, "type", options=["gaussian"])
"gaussian"

The last call should error, but instead returns "gaussian".