diff --git a/Project.toml b/Project.toml
index 63a0fbf..db20961 100644
--- a/Project.toml
+++ b/Project.toml
@@ -2,20 +2,7 @@ name = "TranscodingStreams"
 uuid = "3bb67fe8-82b1-5028-8e26-92a6c54297fa"
 license = "MIT"
 authors = ["Kenta Sato <bicycle1885@gmail.com>"]
-version = "0.11.1"
-
-[deps]
-Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
-Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
-
-[weakdeps]
-Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
-Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
-
-[extensions]
-TestExt = ["Test", "Random"]
+version = "0.11.2"
 
 [compat]
-Random = "1"
-Test = "1"
 julia = "1.6"
diff --git a/ext/TestExt.jl b/ext/TestExt.jl
deleted file mode 100644
index 467c9ac..0000000
--- a/ext/TestExt.jl
+++ /dev/null
@@ -1,157 +0,0 @@
-module TestExt
-
-using Test: Test
-using Random: seed!, randstring
-
-using TranscodingStreams: TranscodingStreams, initialize, finalize, transcode, 
-    TranscodingStream, NoopStream, buffersize, TOKEN_END
-
-TEST_RANDOM_SEED = 12345
-
-function TranscodingStreams.test_roundtrip_read(encoder, decoder)
-    seed!(TEST_RANDOM_SEED)
-    for n in vcat(0:30, sort!(rand(500:100_000, 30))), alpha in (0x00:0xff, 0x00:0x0f)
-        data = rand(alpha, n)
-        file = IOBuffer(data)
-        stream = decoder(encoder(file))
-        Test.@test hash(read(stream)) == hash(data)
-        close(stream)
-    end
-end
-
-# flush all nested streams and return final data
-function take_all(stream)
-    if stream isa Base.GenericIOBuffer
-        seekstart(stream)
-        read(stream)
-    else
-        write(stream, TranscodingStreams.TOKEN_END)
-        flush(stream)
-        take_all(stream.stream)
-    end
-end
-
-function TranscodingStreams.test_roundtrip_write(encoder, decoder)
-    seed!(TEST_RANDOM_SEED)
-    for n in vcat(0:30, sort!(rand(500:100_000, 30))), alpha in (0x00:0xff, 0x00:0x0f)
-        data = rand(alpha, n)
-        stream = encoder(decoder(IOBuffer()))
-        write(stream, data)
-        Test.@test take_all(stream) == data
-        close(stream)
-    end
-end
-
-function TranscodingStreams.test_roundtrip_transcode(encode, decode)
-    seed!(TEST_RANDOM_SEED)
-    encoder = encode()
-    initialize(encoder)
-    decoder = decode()
-    initialize(decoder)
-    for n in vcat(0:30, sort!(rand(500:100_000, 30))), alpha in (0x00:0xff, 0x00:0x0f)
-        data = rand(alpha, n)
-        Test.@test hash(transcode(decode, transcode(encode, data))) == hash(data)
-        Test.@test hash(transcode(decoder, transcode(encoder, data))) == hash(data)
-    end
-    finalize(encoder)
-    finalize(decoder)
-end
-
-function TranscodingStreams.test_roundtrip_lines(encoder, decoder)
-    seed!(TEST_RANDOM_SEED)
-    lines = String[]
-    buf = IOBuffer()
-    stream = encoder(buf)
-    for i in 1:100_000
-        line = randstring(rand(0:1000))
-        println(stream, line)
-        push!(lines, line)
-    end
-    write(stream, TOKEN_END)
-    flush(stream)
-    seekstart(buf)
-    Test.@test hash(lines) == hash(readlines(decoder(buf)))
-end
-
-function TranscodingStreams.test_roundtrip_seekstart(encoder, decoder)
-    seed!(TEST_RANDOM_SEED)
-    for n in vcat(0:30, sort!(rand(500:100_000, 30))), alpha in (0x00:0xff, 0x00:0x0f)
-        data = rand(alpha, n)
-        file = IOBuffer(data)
-        stream = decoder(encoder(file))
-        for m in vcat(0:min(n,20), rand(0:n, 10))
-            Test.@test read(stream, m) == @view(data[1:m])
-            seekstart(stream)
-        end
-        seekstart(stream)
-        Test.@test read(stream) == data
-        seekstart(stream)
-        Test.@test read(stream) == data
-        close(stream)
-    end
-end
-
-function TranscodingStreams.test_roundtrip_fileio(Encoder, Decoder)
-    data = b"""
-    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nulla sit amet tempus felis. Etiam molestie urna placerat iaculis pellentesque. Maecenas porttitor et dolor vitae posuere. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nunc eget nibh quam. Nullam aliquet interdum fringilla. Duis facilisis, lectus in consectetur varius, lorem sem tempor diam, nec auctor tellus nibh sit amet sapien. In ex nunc, elementum eget facilisis ut, luctus eu orci. Sed sapien urna, accumsan et elit non, auctor pretium massa. Phasellus consectetur nisi suscipit blandit aliquam. Nulla facilisi. Mauris pellentesque sem sit amet mi vestibulum eleifend. Nulla faucibus orci ac lorem efficitur, et blandit orci interdum. Aenean posuere ultrices ex sed rhoncus. Donec malesuada mollis sem, sed varius nunc sodales sed. Curabitur lobortis non justo non tristique.
-    """
-    mktemp() do filename, file
-        stream = TranscodingStream(Encoder(), file)
-        write(stream, data)
-        close(stream)
-        stream = TranscodingStream(Decoder(), open(filename))
-        Test.@test hash(read(stream)) == hash(data)
-        close(stream)
-    end
-end
-
-function TranscodingStreams.test_chunked_read(Encoder, Decoder)
-    seed!(TEST_RANDOM_SEED)
-    alpha = b"色即是空"
-    encoder = Encoder()
-    initialize(encoder)
-    for sharedbuf in false:true
-        for _ in 1:500
-            chunks = [rand(alpha, rand(0:100)) for _ in 1:rand(1:100)]
-            data = mapfoldl(x->transcode(encoder, x), vcat, chunks, init=UInt8[])
-            buffer = NoopStream(IOBuffer(data))
-            ok = true
-            for chunk in chunks
-                stream = TranscodingStream(Decoder(), buffer; stop_on_end=true, sharedbuf)
-                ok &= read(stream) == chunk
-                ok &= position(stream) == length(chunk)
-                ok &= eof(stream)
-                ok &= isreadable(stream)
-                close(stream)
-            end
-            # read without stop_on_end should read the full data.
-            stream = TranscodingStream(Decoder(), IOBuffer(data))
-            ok &= read(stream) == reduce(vcat, chunks)
-            close(stream)
-            Test.@test ok
-        end
-    end
-    finalize(encoder)
-end
-
-function TranscodingStreams.test_chunked_write(Encoder, Decoder)
-    seed!(TEST_RANDOM_SEED)
-    alpha = b"空即是色"
-    encoder = Encoder()
-    initialize(encoder)
-    for _ in 1:500
-        chunks = [rand(alpha, rand(0:100)) for _ in 1:2]
-        data = map(x->transcode(encoder, x), chunks)
-        buffer = IOBuffer()
-        stream = TranscodingStream(Decoder(), buffer, stop_on_end=true)
-        write(stream, vcat(data...))
-        close(stream)
-        ok = true
-        ok &= hash(take!(buffer)) == hash(vcat(chunks...))
-        ok &= buffersize(stream.state.buffer1) == 0
-        Test.@test ok
-    end
-    finalize(encoder)
-end
-
-end # module
diff --git a/src/TranscodingStreams.jl b/src/TranscodingStreams.jl
index 8bdeb28..7ebf353 100644
--- a/src/TranscodingStreams.jl
+++ b/src/TranscodingStreams.jl
@@ -17,17 +17,4 @@ include("io.jl")
 include("noop.jl")
 include("transcode.jl")
 
-function test_roundtrip_read end
-function test_roundtrip_write end
-function test_roundtrip_transcode end
-function test_roundtrip_lines end
-function test_roundtrip_seekstart end
-function test_roundtrip_fileio end
-function test_chunked_read end
-function test_chunked_write end
-
-if !isdefined(Base, :get_extension)
-    include("../ext/TestExt.jl")
-end
-
 end # module