diff --git a/.dialyzer_ignore.exs b/.dialyzer_ignore.exs
new file mode 100644
index 0000000..4bfacfa
--- /dev/null
+++ b/.dialyzer_ignore.exs
@@ -0,0 +1,3 @@
+[
+  {"lib/absinthe/plug/graphiql/assets.ex", :pattern_match_cov, 80}
+]
diff --git a/.github/workflows/elixir.yml b/.github/workflows/elixir.yml
index aab2f5c..12e0a5e 100644
--- a/.github/workflows/elixir.yml
+++ b/.github/workflows/elixir.yml
@@ -14,22 +14,31 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
+        elixir:
+          - "1.13"
+          - "1.14"
+          - "1.15"
+        otp:
+          - "24"
+          - "25"
+          - "26"
         include:
-        - pair:
-            elixir: 1.10.4
-            otp: 21.3
-        - pair:
-            elixir: 1.13.3
-            otp: 24.2.1
-          lint: lint
+          - elixir: "1.15"
+            otp: "26"
+            format: true
+        exclude:
+          - elixir: "1.13"
+            otp: "26"
+          - elixir: "1.14"
+            otp: "26"
 
     steps:
     - uses: actions/checkout@v2
 
     - uses: erlef/setup-beam@v1
       with:
-        otp-version: ${{matrix.pair.otp}}
-        elixir-version: ${{matrix.pair.elixir}}
+        otp-version: ${{matrix.otp}}
+        elixir-version: ${{matrix.elixir}}
 
     - name: Restore deps cache
       uses: actions/cache@v2
@@ -47,6 +56,7 @@ jobs:
 
     - name: Check code format
       run: mix format --check-formatted
+      if: ${{ matrix.format }}
 
     - name: Compile dependencies
       run: mix compile
@@ -55,3 +65,16 @@ jobs:
 
     - name: Run unit tests
       run: mix test
+
+    - name: Cache/uncache PLTs
+      uses: actions/cache@v3
+      with:
+        path: |
+          priv/plts
+        key: "${{ runner.os }}-\
+              erlang-${{ matrix.otp }}-\
+              elixir-${{ matrix.elixir }}-\
+              ${{ hashFiles('mix.lock') }}"
+
+    - name: Run Dialyzer
+      run: mix dialyzer
diff --git a/.gitignore b/.gitignore
index 42881f9..2ef81b4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,4 +6,5 @@ erl_crash.dump
 *.ez
 .DS_Store
 .tool-versions
-.elixir_ls
\ No newline at end of file
+.elixir_ls
+priv/plts
diff --git a/config/config.exs b/config/config.exs
index 66f611d..102c269 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -1,6 +1,6 @@
 # This file is responsible for configuring your application
 # and its dependencies with the aid of the Mix.Config module.
-use Mix.Config
+import Config
 
 # This configuration is loaded before any dependency and is restricted
 # to this project. If another project depends on this project, this
@@ -18,7 +18,7 @@ use Mix.Config
 #
 # Or configure a 3rd-party app:
 #
-config :logger, level: :warn
+config :logger, level: :warning
 #
 
 # It is also possible to import configuration files, relative to this
diff --git a/lib/absinthe/plug/graphiql/graphiql_playground.html.eex b/lib/absinthe/plug/graphiql/graphiql_playground.html.eex
index 35c75d9..52e608e 100644
--- a/lib/absinthe/plug/graphiql/graphiql_playground.html.eex
+++ b/lib/absinthe/plug/graphiql/graphiql_playground.html.eex
@@ -58,9 +58,7 @@ add "&raw" to the end of the URL within a browser.
     var options = {};
     var protocol = window.location.protocol === "https:" ? "wss:" : "ws:";
 
-    <%= if default_url do %>
-      options.endpoint = <%= default_url %>;
-    <% end %>
+    options.endpoint = <%= default_url %>;
 
     <%= if socket_url do %>
       options.subscriptionEndpoint = <%= socket_url %>;
diff --git a/lib/absinthe/plug/request/query.ex b/lib/absinthe/plug/request/query.ex
index 2a377de..0f01b99 100644
--- a/lib/absinthe/plug/request/query.ex
+++ b/lib/absinthe/plug/request/query.ex
@@ -146,7 +146,7 @@ defmodule Absinthe.Plug.Request.Query do
   # DOCUMENT PROVIDERS
   #
 
-  @spec calculate_document_providers(map) :: [Absinthe.Plug.DocumentProvider.t(), ...]
+  @spec calculate_document_providers(map) :: [Absinthe.Plug.DocumentProvider.t()]
   defp calculate_document_providers(%{document_providers: {module, fun}} = config)
        when is_atom(fun) do
     apply(module, fun, [config])
diff --git a/mix.exs b/mix.exs
index 02082de..708462e 100644
--- a/mix.exs
+++ b/mix.exs
@@ -14,7 +14,12 @@ defmodule Absinthe.Plug.Mixfile do
       package: package(),
       source_url: "https://github.com/absinthe-graphql/absinthe_plug",
       docs: [source_ref: "v#{@version}", main: "Absinthe.Plug"],
-      deps: deps()
+      deps: deps(),
+      dialyzer: [
+        plt_add_apps: [:mix],
+        plt_add_deps: :apps_direct,
+        plt_file: {:no_warn, "priv/plts/project.plt"}
+      ]
     ]
   end
 
@@ -42,10 +47,11 @@ defmodule Absinthe.Plug.Mixfile do
 
   defp deps do
     [
-      {:absinthe, "~> 1.5"},
+      {:absinthe, "~> 1.7"},
       {:plug, "~> 1.4"},
       {:jason, ">= 0.0.0", only: [:dev, :test]},
-      {:ex_doc, "~> 0.20", only: :dev}
+      {:ex_doc, "~> 0.20", only: :dev},
+      {:dialyxir, "~> 1.3", only: [:dev, :test], runtime: false}
     ]
   end
 end
diff --git a/mix.lock b/mix.lock
index ea71c6d..dcd0e60 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,14 +1,16 @@
 %{
-  "absinthe": {:hex, :absinthe, "1.7.2", "40e40ad9965e469f052264e47370a77365c1ff8810d68dae2bfb2dab462df2dd", [:mix], [{:dataloader, "~> 1.0.0", [hex: :dataloader, repo: "hexpm", optional: true]}, {:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}, {:nimble_parsec, "~> 1.2.2 or ~> 1.3.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}, {:opentelemetry_process_propagator, "~> 0.2.1", [hex: :opentelemetry_process_propagator, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "cb849c6eae613257191f200864301e5f3bc3bdf8d2792c165839e64b7c5a26b9"},
+  "absinthe": {:hex, :absinthe, "1.7.3", "128f9de8d8feab761a50483011c2652074de0a670316d0e24a4979daeb460c8f", [:mix], [{:dataloader, "~> 1.0.0", [hex: :dataloader, repo: "hexpm", optional: true]}, {:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}, {:nimble_parsec, "~> 1.2.2 or ~> 1.3.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}, {:opentelemetry_process_propagator, "~> 0.2.1", [hex: :opentelemetry_process_propagator, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "6def91514f023832dbb3433baa166366881648932211f2e8146f9792b08b7bb3"},
+  "dialyxir": {:hex, :dialyxir, "1.3.0", "fd1672f0922b7648ff9ce7b1b26fcf0ef56dda964a459892ad15f6b4410b5284", [:mix], [{:erlex, ">= 0.2.6", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "00b2a4bcd6aa8db9dcb0b38c1225b7277dca9bc370b6438715667071a304696f"},
   "earmark": {:hex, :earmark, "1.4.4", "4821b8d05cda507189d51f2caeef370cf1e18ca5d7dfb7d31e9cafe6688106a4", [:mix], [], "hexpm", "1f93aba7340574847c0f609da787f0d79efcab51b044bb6e242cae5aca9d264d"},
   "earmark_parser": {:hex, :earmark_parser, "1.4.10", "6603d7a603b9c18d3d20db69921527f82ef09990885ed7525003c7fe7dc86c56", [:mix], [], "hexpm", "8e2d5370b732385db2c9b22215c3f59c84ac7dda7ed7e544d7c459496ae519c0"},
+  "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
   "ex_doc": {:hex, :ex_doc, "0.23.0", "a069bc9b0bf8efe323ecde8c0d62afc13d308b1fa3d228b65bca5cf8703a529d", [:mix], [{:earmark_parser, "~> 1.4.0", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}], "hexpm", "f5e2c4702468b2fd11b10d39416ddadd2fcdd173ba2a0285ebd92c39827a5a16"},
   "jason": {:hex, :jason, "1.2.2", "ba43e3f2709fd1aa1dce90aaabfd039d000469c05c56f0b8e31978e03fa39052", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "18a228f5f0058ee183f29f9eae0805c6e59d61c3b006760668d8d18ff0d12179"},
   "makeup": {:hex, :makeup, "1.0.5", "d5a830bc42c9800ce07dd97fa94669dfb93d3bf5fcf6ea7a0c67b2e0e4a7f26c", [:mix], [{:nimble_parsec, "~> 0.5 or ~> 1.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "cfa158c02d3f5c0c665d0af11512fed3fba0144cf1aadee0f2ce17747fba2ca9"},
   "makeup_elixir": {:hex, :makeup_elixir, "0.14.1", "4f0e96847c63c17841d42c08107405a005a2680eb9c7ccadfd757bd31dabccfb", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "f2438b1a80eaec9ede832b5c41cd4f373b38fd7aa33e3b22d9db79e640cbde11"},
-  "mime": {:hex, :mime, "1.4.0", "5066f14944b470286146047d2f73518cf5cca82f8e4815cf35d196b58cf07c47", [:mix], [], "hexpm", "75fa42c4228ea9a23f70f123c74ba7cece6a03b1fd474fe13f6a7a85c6ea4ff6"},
+  "mime": {:hex, :mime, "2.0.5", "dc34c8efd439abe6ae0343edbb8556f4d63f178594894720607772a041b04b02", [:mix], [], "hexpm", "da0d64a365c45bc9935cc5c8a7fc5e49a0e0f9932a761c55d6c52b142780a05c"},
   "nimble_parsec": {:hex, :nimble_parsec, "1.3.1", "2c54013ecf170e249e9291ed0a62e5832f70a476c61da16f6aac6dca0189f2af", [:mix], [], "hexpm", "2682e3c0b2eb58d90c6375fc0cc30bc7be06f365bf72608804fb9cffa5e1b167"},
-  "plug": {:hex, :plug, "1.11.0", "f17217525597628298998bc3baed9f8ea1fa3f1160aa9871aee6df47a6e4d38e", [:mix], [{:mime, "~> 1.0", [hex: :mime, repo: "hexpm", optional: false]}, {:plug_crypto, "~> 1.1.1 or ~> 1.2", [hex: :plug_crypto, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "2d9c633f0499f9dc5c2fd069161af4e2e7756890b81adcbb2ceaa074e8308876"},
-  "plug_crypto": {:hex, :plug_crypto, "1.2.0", "1cb20793aa63a6c619dd18bb33d7a3aa94818e5fd39ad357051a67f26dfa2df6", [:mix], [], "hexpm", "a48b538ae8bf381ffac344520755f3007cc10bd8e90b240af98ea29b69683fc2"},
-  "telemetry": {:hex, :telemetry, "0.4.3", "a06428a514bdbc63293cd9a6263aad00ddeb66f608163bdec7c8995784080818", [:rebar3], [], "hexpm", "eb72b8365ffda5bed68a620d1da88525e326cb82a75ee61354fc24b844768041"},
+  "plug": {:hex, :plug, "1.14.2", "cff7d4ec45b4ae176a227acd94a7ab536d9b37b942c8e8fa6dfc0fff98ff4d80", [:mix], [{:mime, "~> 1.0 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}, {:plug_crypto, "~> 1.1.1 or ~> 1.2", [hex: :plug_crypto, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4.3 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "842fc50187e13cf4ac3b253d47d9474ed6c296a8732752835ce4a86acdf68d13"},
+  "plug_crypto": {:hex, :plug_crypto, "1.2.5", "918772575e48e81e455818229bf719d4ab4181fcbf7f85b68a35620f78d89ced", [:mix], [], "hexpm", "26549a1d6345e2172eb1c233866756ae44a9609bd33ee6f99147ab3fd87fd842"},
+  "telemetry": {:hex, :telemetry, "1.2.1", "68fdfe8d8f05a8428483a97d7aab2f268aaff24b49e0f599faa091f1d4e7f61c", [:rebar3], [], "hexpm", "dad9ce9d8effc621708f99eac538ef1cbe05d6a874dd741de2e689c47feafed5"},
 }