diff --git a/mix.exs b/mix.exs
index 7893b8438..f84191321 100644
--- a/mix.exs
+++ b/mix.exs
@@ -208,7 +208,8 @@ defmodule Pleroma.Mixfile do
       {:excoveralls, "0.12.3", only: :test},
       {:hackney, "~> 1.18.0", override: true},
       {:mox, "~> 1.0", only: :test},
-      {:websocket_client, git: "https://github.com/jeremyong/websocket_client.git", only: :test}
+      {:mint, "~> 1.4", only: :test, override: true},
+      {:mint_web_socket, "~> 0.3.0", only: :test}
     ] ++ oauth_deps()
   end
 
diff --git a/mix.lock b/mix.lock
index 817240538..81f7e4399 100644
--- a/mix.lock
+++ b/mix.lock
@@ -79,6 +79,7 @@
   "mime": {:hex, :mime, "1.6.0", "dabde576a497cef4bbdd60aceee8160e02a6c89250d6c0b29e56c0dfb00db3d2", [:mix], [], "hexpm", "31a1a8613f8321143dde1dafc36006a17d28d02bdfecb9e95a880fa7aabd19a7"},
   "mimerl": {:hex, :mimerl, "1.2.0", "67e2d3f571088d5cfd3e550c383094b47159f3eee8ffa08e64106cdf5e981be3", [:rebar3], [], "hexpm", "f278585650aa581986264638ebf698f8bb19df297f66ad91b18910dfc6e19323"},
   "mint": {:hex, :mint, "1.4.0", "cd7d2451b201fc8e4a8fd86257fb3878d9e3752899eb67b0c5b25b180bde1212", [:mix], [{:castore, "~> 0.1.0", [hex: :castore, repo: "hexpm", optional: true]}], "hexpm", "10a99e144b815cbf8522dccbc8199d15802440fc7a64d67b6853adb6fa170217"},
+  "mint_web_socket": {:hex, :mint_web_socket, "0.3.0", "c9e130dcc778d673fd713eb66434e16cf7d89cee0754e75f26f8bd9a9e592b63", [:mix], [{:mint, "~> 1.4 and >= 1.4.1", [hex: :mint, repo: "hexpm", optional: false]}], "hexpm", "0605bc3fa684e1a7719b22a3f74be4de5e6a16dd43ac18ebcea72e2adc33b532"},
   "mochiweb": {:hex, :mochiweb, "2.18.0", "eb55f1db3e6e960fac4e6db4e2db9ec3602cc9f30b86cd1481d56545c3145d2e", [:rebar3], [], "hexpm"},
   "mock": {:hex, :mock, "0.3.7", "75b3bbf1466d7e486ea2052a73c6e062c6256fb429d6797999ab02fa32f29e03", [:mix], [{:meck, "~> 0.9.2", [hex: :meck, repo: "hexpm", optional: false]}], "hexpm", "4da49a4609e41fd99b7836945c26f373623ea968cfb6282742bcb94440cf7e5c"},
   "mogrify": {:hex, :mogrify, "0.9.1", "a26f107c4987477769f272bd0f7e3ac4b7b75b11ba597fd001b877beffa9c068", [:mix], [], "hexpm", "134edf189337d2125c0948bf0c228fdeef975c594317452d536224069a5b7f05"},
diff --git a/test/pleroma/integration/mastodon_websocket_test.exs b/test/pleroma/integration/mastodon_websocket_test.exs
index 2d4c7f63b..5599ce030 100644
--- a/test/pleroma/integration/mastodon_websocket_test.exs
+++ b/test/pleroma/integration/mastodon_websocket_test.exs
@@ -28,21 +28,21 @@ defmodule Pleroma.Integration.MastodonWebsocketTest do
         qs -> @path <> qs
       end
 
-    WebsocketClient.start_link(self(), path, headers)
+    WebsocketClient.connect(self(), path, headers)
   end
 
   test "refuses invalid requests" do
     capture_log(fn ->
-      assert {:error, {404, _}} = start_socket()
-      assert {:error, {404, _}} = start_socket("?stream=ncjdk")
+      assert {:error, %Mint.WebSocket.UpgradeFailureError{status_code: 404}} = start_socket()
+      assert {:error, %Mint.WebSocket.UpgradeFailureError{status_code: 404}} = start_socket("?stream=ncjdk")
       Process.sleep(30)
     end)
   end
 
   test "requires authentication and a valid token for protected streams" do
     capture_log(fn ->
-      assert {:error, {401, _}} = start_socket("?stream=user&access_token=aaaaaaaaaaaa")
-      assert {:error, {401, _}} = start_socket("?stream=user")
+      assert {:error, %Mint.WebSocket.UpgradeFailureError{status_code: 401}} = start_socket("?stream=user&access_token=aaaaaaaaaaaa")
+      assert {:error, %Mint.WebSocket.UpgradeFailureError{status_code: 401}} = start_socket("?stream=user")
       Process.sleep(30)
     end)
   end
@@ -102,7 +102,7 @@ defmodule Pleroma.Integration.MastodonWebsocketTest do
       assert {:ok, _} = start_socket("?stream=user&access_token=#{token.token}")
 
       capture_log(fn ->
-        assert {:error, {401, _}} = start_socket("?stream=user")
+        assert {:error, %Mint.WebSocket.UpgradeFailureError{status_code: 401}} = start_socket("?stream=user")
         Process.sleep(30)
       end)
     end
@@ -111,7 +111,7 @@ defmodule Pleroma.Integration.MastodonWebsocketTest do
       assert {:ok, _} = start_socket("?stream=user:notification&access_token=#{token.token}")
 
       capture_log(fn ->
-        assert {:error, {401, _}} = start_socket("?stream=user:notification")
+        assert {:error, %Mint.WebSocket.UpgradeFailureError{status_code: 401}} = start_socket("?stream=user:notification")
         Process.sleep(30)
       end)
     end
@@ -120,7 +120,7 @@ defmodule Pleroma.Integration.MastodonWebsocketTest do
       assert {:ok, _} = start_socket("?stream=user", [{"Sec-WebSocket-Protocol", token.token}])
 
       capture_log(fn ->
-        assert {:error, {401, _}} =
+        assert {:error, %Mint.WebSocket.UpgradeFailureError{status_code: 401}} =
                  start_socket("?stream=user", [{"Sec-WebSocket-Protocol", "I am a friend"}])
 
         Process.sleep(30)
diff --git a/test/support/websocket_client.ex b/test/support/websocket_client.ex
index d149b324e..afcd0e8c7 100644
--- a/test/support/websocket_client.ex
+++ b/test/support/websocket_client.ex
@@ -3,60 +3,199 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Integration.WebsocketClient do
-  # https://github.com/phoenixframework/phoenix/blob/master/test/support/websocket_client.exs
+  @moduledoc """
+  A WebSocket client used to test Mastodon API streaming
+
+  Based on Phoenix Framework's WebsocketClient
+  https://github.com/phoenixframework/phoenix/blob/master/test/support/websocket_client.exs
+  """
+
+  use GenServer
+  import Kernel, except: [send: 2]
+
+  defstruct [
+    :conn,
+    :request_ref,
+    :websocket,
+    :caller,
+    :status,
+    :resp_headers,
+    :sender,
+    closing?: false
+  ]
 
   @doc """
-  Starts the WebSocket server for given ws URL. Received Socket.Message's
-  are forwarded to the sender pid
+  Starts the WebSocket client for given ws URL. `Phoenix.Socket.Message`s
+  received from the server are forwarded to the sender pid.
   """
-  def start_link(sender, url, headers \\ []) do
-    :crypto.start()
-    :ssl.start()
-
-    :websocket_client.start_link(
-      String.to_charlist(url),
-      __MODULE__,
-      [sender],
-      extra_headers: headers
-    )
+  def connect(sender, url, headers \\ []) do
+    with {:ok, socket} <- GenServer.start_link(__MODULE__, {sender}),
+         {:ok, :connected} <- GenServer.call(socket, {:connect, url, headers}) do
+      {:ok, socket}
+    end
   end
 
   @doc """
   Closes the socket
   """
   def close(socket) do
-    send(socket, :close)
+    GenServer.cast(socket, :close)
   end
 
   @doc """
   Sends a low-level text message to the client.
   """
   def send_text(server_pid, msg) do
-    send(server_pid, {:text, msg})
+    GenServer.call(server_pid, {:text, msg})
   end
 
   @doc false
-  def init([sender], _conn_state) do
-    {:ok, %{sender: sender}}
-  end
+  def init({sender}) do
+    state = %__MODULE__{sender: sender}
 
-  @doc false
-  def websocket_handle(frame, _conn_state, state) do
-    send(state.sender, frame)
     {:ok, state}
   end
 
   @doc false
-  def websocket_info({:text, msg}, _conn_state, state) do
-    {:reply, {:text, msg}, state}
-  end
+  def handle_call({:connect, url, headers}, from, state) do
+    uri = URI.parse(url)
 
-  def websocket_info(:close, _conn_state, _state) do
-    {:close, <<>>, "done"}
+    http_scheme =
+      case uri.scheme do
+        "ws" -> :http
+        "wss" -> :https
+      end
+
+    ws_scheme =
+      case uri.scheme do
+        "ws" -> :ws
+        "wss" -> :wss
+      end
+
+    path =
+      case uri.query do
+        nil -> uri.path
+        query -> uri.path <> "?" <> query
+      end
+
+    with {:ok, conn} <- Mint.HTTP.connect(http_scheme, uri.host, uri.port),
+         {:ok, conn, ref} <- Mint.WebSocket.upgrade(ws_scheme, conn, path, headers) do
+      state = %{state | conn: conn, request_ref: ref, caller: from}
+      {:noreply, state}
+    else
+      {:error, reason} ->
+        {:reply, {:error, reason}, state}
+
+      {:error, conn, reason} ->
+        {:reply, {:error, reason}, put_in(state.conn, conn)}
+    end
   end
 
   @doc false
-  def websocket_terminate(_reason, _conn_state, _state) do
-    :ok
+  def handle_info(message, state) do
+    case Mint.WebSocket.stream(state.conn, message) do
+      {:ok, conn, responses} ->
+        state = put_in(state.conn, conn) |> handle_responses(responses)
+        if state.closing?, do: do_close(state), else: {:noreply, state}
+
+      {:error, conn, reason, _responses} ->
+        state = put_in(state.conn, conn) |> reply({:error, reason})
+        {:noreply, state}
+
+      :unknown ->
+        {:noreply, state}
+    end
+  end
+
+  defp do_close(state) do
+    # Streaming a close frame may fail if the server has already closed
+    # for writing.
+    _ = stream_frame(state, :close)
+    Mint.HTTP.close(state.conn)
+    {:stop, :normal, state}
+  end
+
+  defp handle_responses(state, responses)
+
+  defp handle_responses(%{request_ref: ref} = state, [{:status, ref, status} | rest]) do
+    put_in(state.status, status)
+    |> handle_responses(rest)
+  end
+
+  defp handle_responses(%{request_ref: ref} = state, [{:headers, ref, resp_headers} | rest]) do
+    put_in(state.resp_headers, resp_headers)
+    |> handle_responses(rest)
+  end
+
+  defp handle_responses(%{request_ref: ref} = state, [{:done, ref} | rest]) do
+    case Mint.WebSocket.new(state.conn, ref, state.status, state.resp_headers) do
+      {:ok, conn, websocket} ->
+        %{state | conn: conn, websocket: websocket, status: nil, resp_headers: nil}
+        |> reply({:ok, :connected})
+        |> handle_responses(rest)
+
+      {:error, conn, reason} ->
+        put_in(state.conn, conn)
+        |> reply({:error, reason})
+    end
+  end
+
+  defp handle_responses(%{request_ref: ref, websocket: websocket} = state, [
+         {:data, ref, data} | rest
+       ])
+       when websocket != nil do
+    case Mint.WebSocket.decode(websocket, data) do
+      {:ok, websocket, frames} ->
+        put_in(state.websocket, websocket)
+        |> handle_frames(frames)
+        |> handle_responses(rest)
+
+      {:error, websocket, reason} ->
+        put_in(state.websocket, websocket)
+        |> reply({:error, reason})
+    end
+  end
+
+  defp handle_responses(state, [_response | rest]) do
+    handle_responses(state, rest)
+  end
+
+  defp handle_responses(state, []), do: state
+
+  defp handle_frames(state, frames) do
+    {frames, state} =
+      Enum.flat_map_reduce(frames, state, fn
+        # prepare to close the connection when a close frame is received
+        {:close, _code, _data}, state ->
+          {[], put_in(state.closing?, true)}
+
+        frame, state ->
+          {[frame], state}
+      end)
+
+    Enum.each(frames, &Kernel.send(state.sender, &1))
+
+    state
+  end
+
+  defp reply(state, response) do
+    if state.caller, do: GenServer.reply(state.caller, response)
+    put_in(state.caller, nil)
+  end
+
+  # Encodes a frame as a binary and sends it along the wire, keeping `conn`
+  # and `websocket` up to date in `state`.
+  defp stream_frame(state, frame) do
+    with {:ok, websocket, data} <- Mint.WebSocket.encode(state.websocket, frame),
+         state = put_in(state.websocket, websocket),
+        {:ok, conn} <- Mint.WebSocket.stream_request_body(state.conn, state.request_ref, data) do
+          {:ok, put_in(state.conn, conn)}
+    else
+      {:error, %Mint.WebSocket{} = websocket, reason} ->
+        {:error, put_in(state.websocket, websocket), reason}
+
+      {:error, conn, reason} ->
+        {:error, put_in(state.conn, conn), reason}
+    end
   end
 end