diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 583756d..cbcc441 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,27 +8,27 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-16.04
+    runs-on: ${{ matrix.os }}
     env:
       MIX_ENV: test
     strategy:
       fail-fast: false
       matrix:
         include:
-          - pair:
-              elixir: 1.6.6
-              otp: 19.3.6.13
-          - pair:
-              elixir: 1.11.4
-              otp: 23.2.7
+          - elixir: 1.12.3
+            otp: 22.3.4.27
+            os: ubuntu-20.04
+          - elixir: 1.17.2
+            otp: 27.1.2
+            os: ubuntu-24.04
             lint: lint
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - uses: erlef/setup-elixir@v1
         with:
-          otp-version: ${{matrix.pair.otp}}
-          elixir-version: ${{matrix.pair.elixir}}
+          otp-version: ${{matrix.otp}}
+          elixir-version: ${{matrix.elixir}}
 
       - name: Install Dependencies
         run: mix deps.get --only test
diff --git a/mix.exs b/mix.exs
index f84caa2..05d597a 100644
--- a/mix.exs
+++ b/mix.exs
@@ -8,7 +8,7 @@ defmodule MakeupElixir.Mixfile do
     [
       app: :makeup_elixir,
       version: @version,
-      elixir: "~> 1.6",
+      elixir: "~> 1.12",
       start_permanent: Mix.env() == :prod,
       deps: deps(),
       package: package(),
diff --git a/mix.lock b/mix.lock
index 1a6c470..082d489 100644
--- a/mix.lock
+++ b/mix.lock
@@ -5,6 +5,6 @@
   "makeup": {:hex, :makeup, "1.2.0", "b92e9476c62534bd0e5ea9b9fcf36536ca929b6842549832c71d2533cdbe72f7", [:mix], [{:nimble_parsec, "~> 1.4", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "a7af3614f63cbfde2bbe5823cb3e5369317feca391c3a1f96dab8b6b8b09fdf9"},
   "nimble_parsec": {:hex, :nimble_parsec, "1.4.0", "51f9b613ea62cfa97b25ccc2c1b4216e81df970acd8e16e8d1bdc58fef21370d", [:mix], [], "hexpm", "9c565862810fb383e9838c1dd2d7d2c437b3d13b267414ba6af33e50d2d1cf28"},
   "statistex": {:hex, :statistex, "1.0.0", "f3dc93f3c0c6c92e5f291704cf62b99b553253d7969e9a5fa713e5481cd858a5", [:mix], [], "hexpm", "ff9d8bee7035028ab4742ff52fc80a2aa35cece833cf5319009b52f1b5a86c27"},
-  "unicode": {:hex, :unicode, "1.19.0", "264191eacb1d44039d0dbb9fd936c557431825373b6e7b18d77e80cb0cc344bd", [:mix], [], "hexpm", "ae83bbf54429a67bc6fa9c941a6e9f0ec38dd9c2a32b21583ad511d3b6555631"},
+  "unicode": {:hex, :unicode, "1.20.0", "10189cfe98b03ebb8be6efd00df0936c1c94d75bfbd62cba2bdf958fef3ee4a7", [:mix], [], "hexpm", "fa581cf80b3b1b7f42e4d24a69109dfac465cec27a62c661306c81f4ab35894c"},
   "unicode_set": {:hex, :unicode_set, "1.4.0", "d7f005d5227768fb13a507433925b685be76acfbe6e5a25323c8231b54f59a96", [:mix], [{:nimble_parsec, "~> 1.2.2 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}, {:unicode, "~> 1.13", [hex: :unicode, repo: "hexpm", optional: false]}], "hexpm", "096d84ecd1f7965b0f0073f00a51bdc9c8d400f085730fcee6f735f1c2d676ef"},
 }
diff --git a/test/makeup/lexers/elixir_lexer/elixir_lexer_sigil_lexer_test.exs b/test/makeup/lexers/elixir_lexer/elixir_lexer_sigil_lexer_test.exs
new file mode 100644
index 0000000..c64f01d
--- /dev/null
+++ b/test/makeup/lexers/elixir_lexer/elixir_lexer_sigil_lexer_test.exs
@@ -0,0 +1,24 @@
+defmodule ElixirLexerSigilLexerTest do
+  use ExUnit.Case, async: false
+  import Makeup.Lexers.ElixirLexer.Testing, only: [lex: 1]
+
+  describe "custom lexers for sigils" do
+    test "can register a custom lexer" do
+      defmodule MyCustomLexer do
+        def lex(input) do
+          [{:keyword, %{}, input}]
+        end
+      end
+
+      Makeup.Lexers.ElixirLexer.register_sigil_lexer("H", MyCustomLexer)
+
+      assert lex("~H|Hello, world!|") == [
+               {:string_sigil, %{}, "~H|"},
+               {:keyword, %{}, "Hello, world!"},
+               {:string_sigil, %{}, "|"}
+             ]
+    after
+      Application.put_env(:makeup_elixir, :sigil_lexers, %{})
+    end
+  end
+end
diff --git a/test/makeup/lexers/elixir_lexer/elixir_lexer_tokenizer_test.exs b/test/makeup/lexers/elixir_lexer/elixir_lexer_tokenizer_test.exs
index 31c7127..1dfb3f9 100644
--- a/test/makeup/lexers/elixir_lexer/elixir_lexer_tokenizer_test.exs
+++ b/test/makeup/lexers/elixir_lexer/elixir_lexer_tokenizer_test.exs
@@ -695,22 +695,4 @@ defmodule ElixirLexerTokenizerTestSnippet do
              {:punctuation, %{group_id: "group-1"}, "}"}
            ]
   end
-
-  describe "custom lexers for sigils" do
-    test "can register a custom lexer" do
-      defmodule MyCustomLexer do
-        def lex(input) do
-          [{:keyword, %{}, input}]
-        end
-      end
-
-      Makeup.Lexers.ElixirLexer.register_sigil_lexer("H", MyCustomLexer)
-
-      assert lex("~H|Hello, world!|") == [
-               {:string_sigil, %{}, "~H|"},
-               {:keyword, %{}, "Hello, world!"},
-               {:string_sigil, %{}, "|"}
-             ]
-    end
-  end
 end