diff --git a/bucky-core.gemspec b/bucky-core.gemspec
index 4cdf63f9..4ff227cf 100644
--- a/bucky-core.gemspec
+++ b/bucky-core.gemspec
@@ -43,7 +43,7 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency 'addressable', '~> 2.5'
   spec.add_runtime_dependency 'color_echo',         '~> 3.1'
   spec.add_runtime_dependency 'json',               '~> 2.3.0'
-  spec.add_runtime_dependency 'nokogiri',           '~> 1.11.1'
+  spec.add_runtime_dependency 'nokogiri',           '1.11.1'
   spec.add_runtime_dependency 'parallel',           '~> 1.11'
   spec.add_runtime_dependency 'ruby-mysql',         '~> 2.9'
   spec.add_runtime_dependency 'selenium-webdriver', '4.24'
diff --git a/lib/bucky/test_equipment/user_operation/user_operation_helper.rb b/lib/bucky/test_equipment/user_operation/user_operation_helper.rb
index 0e561480..2c121acb 100644
--- a/lib/bucky/test_equipment/user_operation/user_operation_helper.rb
+++ b/lib/bucky/test_equipment/user_operation/user_operation_helper.rb
@@ -27,7 +27,7 @@ def back(_)
 
         def input(args)
           # when input successfully, return of click is nil.
-          wait_until_helper((args || {}).fetch(:timeout, 5), 0.1, Selenium::WebDriver::Error::StaleElementReferenceError) { @pages.get_part(args).send_keys(args[:word]).nil? }
+          wait_until_helper((args || {}).fetch(:timeout, 10), 0.1, Selenium::WebDriver::Error::StaleElementReferenceError) { @pages.get_part(args).send_keys(args[:word]).nil? }
         end
 
         # Clear textbox
@@ -48,14 +48,14 @@ def refresh(_)
         def switch_to_next_window(_)
           window_index = @driver.window_handles.index(@driver.window_handle)
           windows_number = @driver.window_handles.size
-          unless window_index+1 == windows_number
-            @driver.switch_to.window(@driver.window_handles[window_index+1])
-          end
+          return if window_index + 1 == windows_number
+
+          @driver.switch_to.window(@driver.window_handles[window_index + 1])
         end
 
         def switch_to_previous_window(_)
           window_index = @driver.window_handles.index(@driver.window_handle)
-          @driver.switch_to.window(@driver.window_handles[window_index-1])
+          @driver.switch_to.window(@driver.window_handles[window_index - 1])
         end
 
         def switch_to_newest_window(_)
@@ -75,7 +75,7 @@ def switch_to_the_window(args)
         def close(_)
           window_index = @driver.window_handles.index(@driver.window_handle)
           @driver.close
-          @driver.switch_to.window(@driver.window_handles[window_index-1])
+          @driver.switch_to.window(@driver.window_handles[window_index - 1])
         end
 
         def stop(_)
@@ -102,7 +102,7 @@ def choose(args)
 
         # Alert accept
         def accept_alert(args)
-          alert = wait_until_helper((args || {}).fetch(:timeout, 5), 0.1, Selenium::WebDriver::Error::NoAlertPresentError) { @driver.switch_to.alert }
+          alert = wait_until_helper((args || {}).fetch(:timeout, 5), 0.1, Selenium::WebDriver::Error::StaleElementReferenceError) { @driver.switch_to.alert }
           alert.accept
         end