diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index ea502a426..555a39a66 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -195,8 +195,8 @@ class ApplicationController < ActionController::Base
   # /tags?search[name]=touhou&search[category]=&search[order]=
   # => /tags?search[name]=touhou
   def normalize_search
-    return unless request.get? && params[:action] == "index"
-    params[:search] = search_params
+    return unless request.get?
+    params[:search] ||= ActionController::Parameters.new
 
     deep_reject_blank = lambda do |hash|
       hash.reject { |k, v| v.blank? || (v.is_a?(Hash) && deep_reject_blank.call(v).blank?) }
@@ -210,9 +210,7 @@ class ApplicationController < ActionController::Base
   end
 
   def search_params
-    search_params = params.fetch(:search, {})
-    search_params = ActionController::Parameters.new unless search_params.is_a?(ActionController::Parameters)
-    search_params.permit!
+    params.fetch(:search, {}).permit!
   end
 
   def set_safe_mode
diff --git a/test/functional/application_controller_test.rb b/test/functional/application_controller_test.rb
index 47338564a..4d3e9b8f9 100644
--- a/test/functional/application_controller_test.rb
+++ b/test/functional/application_controller_test.rb
@@ -35,10 +35,5 @@ class ApplicationControllerTest < ActionDispatch::IntegrationTest
         assert_response 410
       end
     end
-
-    should "normalize search params" do
-      get tags_path, params: { search: { name: "bkub", post_count: "" } }
-      assert_redirected_to tags_path(search: { name: "bkub" })
-    end
   end
 end