diff --git a/.formatter.exs b/.formatter.exs
index af6c7f8..8da9f9c 100644
--- a/.formatter.exs
+++ b/.formatter.exs
@@ -1,4 +1,3 @@
-# Used by "mix format"
 [
-  inputs: [".formatter.exs", "{config,lib,test}/**/*.{ex,exs}"]
+  inputs: ["*.exs", "{lib,test}/**/*.{ex,exs}"]
 ]
diff --git a/.gitignore b/.gitignore
index e790527..f8f26cf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,24 +1,8 @@
-# The directory Mix will write compiled artifacts to.
 /_build/
-
-# If you run "mix test --cover", coverage assets end up here.
 /cover/
-
-# The directory Mix downloads your dependencies sources to.
 /deps/
-
-# Where third-party dependencies like ExDoc output generated docs.
 /doc/
-
-# Ignore .fetch files in case you like to edit your project deps locally.
-/.fetch
-
-# If the VM crashes, it generates a dump, let's ignore it too.
+/priv/plts/
 erl_crash.dump
-
-# Also ignore archive artifacts (built via "mix archive.build").
 *.ez
-
-# Ignore package tarball (built via "mix hex.build").
 delta-*.tar
-
diff --git a/.iex.exs b/.iex.exs
deleted file mode 100644
index 6a2e3f0..0000000
--- a/.iex.exs
+++ /dev/null
@@ -1,5 +0,0 @@
-alias Delta.{
-  Op,
-  Attr,
-  EmbedHandler
-}
diff --git a/lib/delta/embed_handler.ex b/lib/delta/embed_handler.ex
index af8099b..faa8686 100644
--- a/lib/delta/embed_handler.ex
+++ b/lib/delta/embed_handler.ex
@@ -51,8 +51,7 @@ defmodule Delta.EmbedHandler do
         %{"retain" => %{"image" => "https://quilljs.com/assets/images/icon.png"}}
       ]
   """
-  @type t :: module()
-  @type embed :: map()
+  @type embed :: map() | list(map())
 
   @callback name() :: binary()
   @callback compose(any(), any(), keep_nil? :: boolean()) :: embed()
diff --git a/mix.exs b/mix.exs
index 7fe410e..ab69d01 100644
--- a/mix.exs
+++ b/mix.exs
@@ -8,6 +8,7 @@ defmodule Delta.MixProject do
 
   def project do
     [
+      name: @name,
       app: @app,
       version: @version,
       elixir: "~> 1.18",
@@ -15,13 +16,17 @@ defmodule Delta.MixProject do
       package: package(),
       deps: deps(),
       elixirc_paths: elixirc_paths(Mix.env()),
-      name: @name,
       docs: [
         main: @name,
         source_url: @github,
         homepage_url: @github,
         canonical: "https://hexdocs.pm/#{@app}",
         extras: ["README.md", "CHANGELOG.md"]
+      ],
+      dialyzer: [
+        plt_file: {:no_warn, "priv/plts/project.plt"},
+        plt_add_apps: [:ex_unit],
+        list_unused_filters: true
       ]
     ]
   end
@@ -39,7 +44,8 @@ defmodule Delta.MixProject do
 
   defp deps do
     [
-      {:diff_match_patch, "~> 0.2"},
+      {:diff_match_patch, "~> 0.3"},
+      {:dialyxir, "~> 1.4.5", only: [:dev, :test], runtime: false},
       {:diffy, "~> 1.1"},
       {:ex_doc, ">= 0.0.0", only: :dev, runtime: false}
     ]
diff --git a/mix.lock b/mix.lock
index b92aaa7..9563732 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,7 +1,9 @@
 %{
+  "dialyxir": {:hex, :dialyxir, "1.4.7", "dda948fcee52962e4b6c5b4b16b2d8fa7d50d8645bbae8b8685c3f9ecb7f5f4d", [:mix], [{:erlex, ">= 0.2.8", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "b34527202e6eb8cee198efec110996c25c5898f43a4094df157f8d28f27d9efe"},
   "diff_match_patch": {:hex, :diff_match_patch, "0.3.0", "8741299f6e43d701dc160e28738440f53af0969e3cea79d2d8e57f8dcb631d26", [:mix], [], "hexpm", "cf377f0d7dc4d40cd68fc580c26047351f217be729565e944f8cea36b19013b7"},
   "diffy": {:hex, :diffy, "1.1.2", "7060e34fd512f210056b7e66e8d315cb90d06b97a6656d92fc299eb91692e36e", [:rebar3], [{:proper, "~> 1.2.0", [hex: :proper, repo: "hexpm", optional: false]}, {:zotonic_stdlib, "1.2.3", [hex: :zotonic_stdlib, repo: "hexpm", optional: false]}], "hexpm", "9a59bbdcafb6b115b5099711f7f114edb00be11658cef08ef26e04f8040c7149"},
   "earmark_parser": {:hex, :earmark_parser, "1.4.44", "f20830dd6b5c77afe2b063777ddbbff09f9759396500cdbe7523efd58d7a339c", [:mix], [], "hexpm", "4778ac752b4701a5599215f7030989c989ffdc4f6df457c5f36938cc2d2a2750"},
+  "erlex": {:hex, :erlex, "0.2.8", "cd8116f20f3c0afe376d1e8d1f0ae2452337729f68be016ea544a72f767d9c12", [:mix], [], "hexpm", "9d66ff9fedf69e49dc3fd12831e12a8a37b76f8651dd21cd45fcf5561a8a7590"},
   "ex_doc": {:hex, :ex_doc, "0.40.1", "67542e4b6dde74811cfd580e2c0149b78010fd13001fda7cfeb2b2c2ffb1344d", [:mix], [{:earmark_parser, "~> 1.4.44", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.0", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14 or ~> 1.0", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1 or ~> 1.0", [hex: :makeup_erlang, repo: "hexpm", optional: false]}, {:makeup_html, ">= 0.1.0", [hex: :makeup_html, repo: "hexpm", optional: true]}], "hexpm", "bcef0e2d360d93ac19f01a85d58f91752d930c0a30e2681145feea6bd3516e00"},
   "makeup": {:hex, :makeup, "1.2.1", "e90ac1c65589ef354378def3ba19d401e739ee7ee06fb47f94c687016e3713d1", [:mix], [{:nimble_parsec, "~> 1.4", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "d36484867b0bae0fea568d10131197a4c2e47056a6fbe84922bf6ba71c8d17ce"},
   "makeup_elixir": {:hex, :makeup_elixir, "1.0.1", "e928a4f984e795e41e3abd27bfc09f51db16ab8ba1aebdba2b3a575437efafc2", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "7284900d412a3e5cfd97fdaed4f5ed389b8f2b4cb49efc0eb3bd10e2febf9507"},
diff --git a/test/support/case.ex b/test/support/case.ex
index fabf740..aec676b 100644
--- a/test/support/case.ex
+++ b/test/support/case.ex
@@ -4,7 +4,6 @@ defmodule Delta.Support.Case do
 
   using do
     quote do
-      alias Delta
       alias Delta.Attr
       alias Delta.Op
       alias Delta.Support.MapEmbed