1 files changed, 11 insertions, 1 deletions
diff --git a/ext/tk/lib/tkextlib/bwidget/scrolledwindow.rb b/ext/tk/lib/tkextlib/bwidget/scrolledwindow.rb
index 3599fd8459..ea5a18cc66 100644
--- a/ext/tk/lib/tkextlib/bwidget/scrolledwindow.rb
+++ b/ext/tk/lib/tkextlib/bwidget/scrolledwindow.rb
@@ -17,7 +17,17 @@ end
 class Tk::BWidget::ScrolledWindow
   TkCommandNames = ['ScrolledWindow'.freeze].freeze
   WidgetClassName = 'ScrolledWindow'.freeze
-  WidgetClassNames[WidgetClassName] = self
+  WidgetClassNames[WidgetClassName] ||= self
+
+  def __strval_optkeys
+    super() << 'sides'
+  end
+  private :__strval_optkeys
+
+  def __boolval_optkeys
+    super() << 'managed'
+  end
+  private :__boolval_optkeys
 
   def get_frame(&b)
     win = window(tk_send_without_enc('getframe'))