diff --git a/lib/jsonapi/rails/action_controller.rb b/lib/jsonapi/rails/action_controller.rb
index e4938c4..a876e74 100644
--- a/lib/jsonapi/rails/action_controller.rb
+++ b/lib/jsonapi/rails/action_controller.rb
@@ -32,29 +32,13 @@ def deserializable_relationship(key, options = {}, &block)
         def _deserializable(key, options, fallback, &block)
           options = options.dup
           klass = options.delete(:class) || Class.new(fallback, &block)
-          use Deserialization, key, klass, options
-        end
-      end
 
-      class Deserialization
-        REQUEST_PARAMETERS_KEY =
-          'action_dispatch.request.request_parameters'.freeze
-        def initialize(app, key, klass)
-          @app = app
-          @deserializable_key = key
-          @deserializable_class = klass
-        end
-
-        def call(env)
-          request = Rack::Request.new(env)
-          body = JSON.parse(request.body.read)
-          deserializable = @deserializable_class.new(body)
-          env[REVERSE_MAPPING_KEY] = deserializable.reverse_mapping
-          (env[REQUEST_PARAMETERS_KEY] ||= {}).tap do |request_parameters|
-            request_parameters[@deserializable_key] = deserializable.to_hash
+          before_action(options) do |controller|
+            resource = klass.new(controller.params[:_jsonapi].to_unsafe_hash)
+            controller.request.env[REVERSE_MAPPING_KEY] =
+              resource.reverse_mapping
+            controller.params[key.to_sym] = resource.to_hash
           end
-
-          @app.call(env)
         end
       end
     end
diff --git a/lib/jsonapi/rails/parser.rb b/lib/jsonapi/rails/parser.rb
index f6b6d52..6774559 100644
--- a/lib/jsonapi/rails/parser.rb
+++ b/lib/jsonapi/rails/parser.rb
@@ -1,13 +1,12 @@
+require 'jsonapi/deserializable'
+
 module JSONAPI
   module Rails
-    module_function
+    PARSER = lambda do |body|
+      data = JSON.parse(body)
+      hash = { _jsonapi: data }
 
-    def parser
-      lambda do |body|
-        data = JSON.parse(body)
-        data = { _json: data } unless data.is_a?(Hash)
-        data.with_indifferent_access
-      end
+      hash.with_indifferent_access
     end
   end
 end
diff --git a/lib/jsonapi/rails/railtie.rb b/lib/jsonapi/rails/railtie.rb
index 9a25076..21ed56e 100644
--- a/lib/jsonapi/rails/railtie.rb
+++ b/lib/jsonapi/rails/railtie.rb
@@ -9,7 +9,6 @@ module JSONAPI
   module Rails
     class Railtie < ::Rails::Railtie
       MEDIA_TYPE = 'application/vnd.api+json'.freeze
-      PARSER = JSONAPI::Rails.parser
       RENDERERS = {
         jsonapi:       JSONAPI::Rails.rails_renderer(SuccessRenderer),
         jsonapi_error: JSONAPI::Rails.rails_renderer(ErrorRenderer)