diff --git a/changelog.d/argon2-passwords.add b/changelog.d/argon2-passwords.add
new file mode 100644
index 000000000..36fd7faf2
--- /dev/null
+++ b/changelog.d/argon2-passwords.add
@@ -0,0 +1 @@
+Added support for argon2 passwords and their conversion for migration from Akkoma fork to upstream.
diff --git a/lib/pleroma/web/plugs/authentication_plug.ex b/lib/pleroma/web/plugs/authentication_plug.ex
index f912a1542..af7d7f45a 100644
--- a/lib/pleroma/web/plugs/authentication_plug.ex
+++ b/lib/pleroma/web/plugs/authentication_plug.ex
@@ -47,6 +47,11 @@ defmodule Pleroma.Web.Plugs.AuthenticationPlug do
     Pleroma.Password.Pbkdf2.verify_pass(password, password_hash)
   end
 
+  def checkpw(password, "$argon2" <> _ = password_hash) do
+    # Handle argon2 passwords for Akkoma migration
+    Argon2.verify_pass(password, password_hash)
+  end
+
   def checkpw(_password, _password_hash) do
     Logger.error("Password hash not recognized")
     false
@@ -56,6 +61,10 @@ defmodule Pleroma.Web.Plugs.AuthenticationPlug do
     do_update_password(user, password)
   end
 
+  def maybe_update_password(%User{password_hash: "$argon2" <> _} = user, password) do
+    do_update_password(user, password)
+  end
+
   def maybe_update_password(user, _), do: {:ok, user}
 
   defp do_update_password(user, password) do
diff --git a/mix.exs b/mix.exs
index df44934d7..0d49a6b45 100644
--- a/mix.exs
+++ b/mix.exs
@@ -203,6 +203,7 @@ defmodule Pleroma.Mixfile do
       {:websock_adapter, "~> 0.5.6"},
       {:oban_live_dashboard, "~> 0.1.1"},
       {:multipart, "~> 0.4.0", optional: true},
+      {:argon2_elixir, "~> 4.0"},
 
       ## dev & test
       {:phoenix_live_reload, "~> 1.3.3", only: :dev},
diff --git a/mix.lock b/mix.lock
index 865e09a4c..01f2eef98 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,5 +1,6 @@
 %{
   "accept": {:hex, :accept, "0.3.5", "b33b127abca7cc948bbe6caa4c263369abf1347cfa9d8e699c6d214660f10cd1", [:rebar3], [], "hexpm", "11b18c220bcc2eab63b5470c038ef10eb6783bcb1fcdb11aa4137defa5ac1bb8"},
+  "argon2_elixir": {:hex, :argon2_elixir, "4.0.0", "7f6cd2e4a93a37f61d58a367d82f830ad9527082ff3c820b8197a8a736648941", [:make, :mix], [{:comeonin, "~> 5.3", [hex: :comeonin, repo: "hexpm", optional: false]}, {:elixir_make, "~> 0.6", [hex: :elixir_make, repo: "hexpm", optional: false]}], "hexpm", "f9da27cf060c9ea61b1bd47837a28d7e48a8f6fa13a745e252556c14f9132c7f"},
   "bandit": {:hex, :bandit, "1.5.5", "df28f1c41f745401fe9e85a6882033f5f3442ab6d30c8a2948554062a4ab56e0", [:mix], [{:hpax, "~> 0.2.0", [hex: :hpax, repo: "hexpm", optional: false]}, {:plug, "~> 1.14", [hex: :plug, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}, {:thousand_island, "~> 1.0", [hex: :thousand_island, repo: "hexpm", optional: false]}, {:websock, "~> 0.5", [hex: :websock, repo: "hexpm", optional: false]}], "hexpm", "f21579a29ea4bc08440343b2b5f16f7cddf2fea5725d31b72cf973ec729079e1"},
   "base62": {:hex, :base62, "1.2.2", "85c6627eb609317b70f555294045895ffaaeb1758666ab9ef9ca38865b11e629", [:mix], [{:custom_base, "~> 0.2.1", [hex: :custom_base, repo: "hexpm", optional: false]}], "hexpm", "d41336bda8eaa5be197f1e4592400513ee60518e5b9f4dcf38f4b4dae6f377bb"},
   "bbcode_pleroma": {:hex, :bbcode_pleroma, "0.2.0", "d36f5bca6e2f62261c45be30fa9b92725c0655ad45c99025cb1c3e28e25803ef", [:mix], [{:nimble_parsec, "~> 0.5", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "19851074419a5fedb4ef49e1f01b30df504bb5dbb6d6adfc135238063bebd1c3"},
diff --git a/test/pleroma/web/plugs/authentication_plug_test.exs b/test/pleroma/web/plugs/authentication_plug_test.exs
index b8acd01c5..bdbf3de32 100644
--- a/test/pleroma/web/plugs/authentication_plug_test.exs
+++ b/test/pleroma/web/plugs/authentication_plug_test.exs
@@ -70,6 +70,24 @@ defmodule Pleroma.Web.Plugs.AuthenticationPlugTest do
     assert "$pbkdf2" <> _ = user.password_hash
   end
 
+  test "with an argon2 hash, it updates to a pkbdf2 hash", %{conn: conn} do
+    user = insert(:user, password_hash: Argon2.hash_pwd_salt("123"))
+    assert "$argon2" <> _ = user.password_hash
+
+    conn =
+      conn
+      |> assign(:auth_user, user)
+      |> assign(:auth_credentials, %{password: "123"})
+      |> AuthenticationPlug.call(%{})
+
+    assert conn.assigns.user.id == conn.assigns.auth_user.id
+    assert conn.assigns.token == nil
+    assert PlugHelper.plug_skipped?(conn, OAuthScopesPlug)
+
+    user = User.get_by_id(user.id)
+    assert "$pbkdf2" <> _ = user.password_hash
+  end
+
   describe "checkpw/2" do
     test "check pbkdf2 hash" do
       hash =
@@ -86,6 +104,14 @@ defmodule Pleroma.Web.Plugs.AuthenticationPlugTest do
       refute AuthenticationPlug.checkpw("password1", hash)
     end
 
+    test "check argon2 hash" do
+      hash =
+        "$argon2id$v=19$m=65536,t=8,p=2$zEMMsTuK5KkL5AFWbX7jyQ$VyaQD7PF6e9btz0oH1YiAkWwIGZ7WNDZP8l+a/O171g"
+
+      assert AuthenticationPlug.checkpw("password", hash)
+      refute AuthenticationPlug.checkpw("password1", hash)
+    end
+
     test "it returns false when hash invalid" do
       hash =
         "psBWV8gxkGOZWBz$PmfCycChoxeJ3GgGzwvhlgacb9mUoZ.KUXNCssekER4SJ7bOK53uXrHNb2e4i8yPFgSKyzaW9CcmrDXWIEMtD1"