diff --git a/lib/open_api_spex/cast_parameters.ex b/lib/open_api_spex/cast_parameters.ex
index 1155cb79..9ec6f92b 100644
--- a/lib/open_api_spex/cast_parameters.ex
+++ b/lib/open_api_spex/cast_parameters.ex
@@ -4,8 +4,6 @@ defmodule OpenApiSpex.CastParameters do
   alias OpenApiSpex.Cast.Error
   alias Plug.Conn
 
-  @default_parsers %{~r/^application\/.*json.*$/ => OpenApi.json_encoder()}
-
   @spec cast(Plug.Conn.t(), Operation.t(), OpenApi.t(), opts :: [OpenApiSpex.cast_opt()]) ::
           {:error, [Error.t()]} | {:ok, Conn.t()}
   def cast(conn, operation, spec, opts \\ []) do
@@ -120,7 +118,7 @@ defmodule OpenApiSpex.CastParameters do
          opts
        ) do
     parsers = Map.get(ext || %{}, "x-parameter-content-parsers", %{})
-    parsers = Map.merge(@default_parsers, parsers)
+    parsers = Map.merge(default_parsers(), parsers)
 
     conn
     |> get_params_by_location(
@@ -134,6 +132,9 @@ defmodule OpenApiSpex.CastParameters do
     end
   end
 
+  defp default_parsers,
+    do: %{~r/^application\/.*json.*$/ => OpenApi.json_encoder()}
+
   defp pre_parse_parameters(%{} = parameters, %{} = parameters_context, parsers) do
     Enum.reduce_while(parameters, Map.new(), fn {key, value}, acc ->
       case pre_parse_parameter(value, Map.get(parameters_context, key, %{}), parsers) do
diff --git a/lib/open_api_spex/controller_specs.ex b/lib/open_api_spex/controller_specs.ex
index 144843e0..d1595579 100644
--- a/lib/open_api_spex/controller_specs.ex
+++ b/lib/open_api_spex/controller_specs.ex
@@ -386,7 +386,9 @@ defmodule OpenApiSpex.ControllerSpecs do
 
     extensions =
       spec
-      |> Enum.filter(fn {key, _val} -> is_atom(key) && String.starts_with?(to_string(key), "x-") end)
+      |> Enum.filter(fn {key, _val} ->
+        is_atom(key) && String.starts_with?(to_string(key), "x-")
+      end)
       |> Map.new(fn {key, value} -> {to_string(key), value} end)
 
     %Operation{
diff --git a/test/cast/string_test.exs b/test/cast/string_test.exs
index 427c616a..eabb5703 100644
--- a/test/cast/string_test.exs
+++ b/test/cast/string_test.exs
@@ -27,7 +27,7 @@ defmodule OpenApiSpex.CastStringTest do
       assert {:error, [error]} = cast(value: "hello", schema: schema)
       assert error.reason == :invalid_format
       assert error.value == "hello"
-      assert error.format == ~r/\d-\d/
+      assert error.format.source == "\\d-\\d"
     end
 
     test "string with format (date time)" do
diff --git a/test/support/schemas.ex b/test/support/schemas.ex
index 65f687fd..0f93748f 100644
--- a/test/support/schemas.ex
+++ b/test/support/schemas.ex
@@ -186,7 +186,7 @@ defmodule OpenApiSpexTest.Schemas do
       type: :object,
       properties: %{
         id: %Schema{type: :integer, description: "User ID"},
-        name: %Schema{type: :string, description: "User name", pattern: ~r/[a-zA-Z][a-zA-Z0-9_]+/},
+        name: %Schema{type: :string, description: "User name", pattern: "[a-zA-Z][a-zA-Z0-9_]+"},
         email: %Schema{type: :string, description: "Email address", format: :email},
         password: %Schema{type: :string, description: "Login password", writeOnly: true},
         age: %Schema{type: :integer, description: "Age"},