MethodError: no method matching position(::StringDecoder{...}) with readuntil

[nalimilan]

julia> readuntil(IOBuffer("noël"), enc"UTF-8", "ë")
"no"

julia> readuntil(IOBuffer("noël"), enc"UTF-8", 'ë')
ERROR: MethodError: no method matching position(::StringDecoder{Encoding{Symbol("UTF-8")},Encoding{Symbol("UTF-8")},Base.GenericIOBuffer{Array{UInt8,1}}})
Closest candidates are:
  position(::Base.Filesystem.File) at filesystem.jl:225
  position(::Base.Libc.FILE) at libc.jl:92
  position(::IOStream) at iostream.jl:188
  ...
Stacktrace:
 [1] mark(::StringDecoder{Encoding{Symbol("UTF-8")},Encoding{Symbol("UTF-8")},Base.GenericIOBuffer{Array{UInt8,1}}}) at ./io.jl:915
 [2] peek at ./iostream.jl:525 [inlined]
 [3] read(::StringDecoder{Encoding{Symbol("UTF-8")},Encoding{Symbol("UTF-8")},Base.GenericIOBuffer{Array{UInt8,1}}}, ::Type{Char}) at ./io.jl:625
 [4] #readuntil#283(::Bool, ::Function, ::StringDecoder{Encoding{Symbol("UTF-8")},Encoding{Symbol("UTF-8")},Base.GenericIOBuffer{Array{UInt8,1}}}, ::Char) at ./io.jl:646
 [5] #readuntil#11 at ./none:0 [inlined]
 [6] readuntil(::Base.GenericIOBuffer{Array{UInt8,1}}, ::Encoding{Symbol("UTF-8")}, ::Char) at /home/milan/.julia/StringEncodings/src/StringEncodings.jl:443
 [7] top-level scope at none:0