diff --git a/include/nana/gui/widgets/listbox.hpp b/include/nana/gui/widgets/listbox.hpp
index d5bb0607..86184718 100644
--- a/include/nana/gui/widgets/listbox.hpp
+++ b/include/nana/gui/widgets/listbox.hpp
@@ -1,7 +1,7 @@
 /**
  *	A List Box Implementation
  *	Nana C++ Library(http://www.nanapro.org)
- *	Copyright(C) 2003-2018 Jinhao(cnjinhao@hotmail.com)
+ *	Copyright(C) 2003-2019 Jinhao(cnjinhao@hotmail.com)
  *
  *	Distributed under the Boost Software License, Version 1.0. 
  *	(See accompanying file LICENSE_1_0.txt or copy at 
@@ -1538,6 +1538,7 @@ the nana::detail::basic_window member pointer scheme
 
 		void enable_single(bool for_selection, bool category_limited);
 		void disable_single(bool for_selection);
+		bool is_single_enabled(bool for_selection) const noexcept;	///< Determines whether the single selection/check is enabled.
 		export_options& def_export_options();
 
 
diff --git a/source/gui/widgets/listbox.cpp b/source/gui/widgets/listbox.cpp
index 0c797c57..d7789748 100644
--- a/source/gui/widgets/listbox.cpp
+++ b/source/gui/widgets/listbox.cpp
@@ -1850,6 +1850,11 @@ namespace nana
 					(for_selection ? single_selection_ : single_check_) = false;
 				}
 
+				bool is_single_enabled(bool for_selection) const noexcept
+				{
+					return (for_selection ? single_selection_ : single_check_);
+				}
+
 				size_type size_item(size_type cat) const
 				{
 					return get(cat)->items.size();
@@ -5959,9 +5964,16 @@ namespace nana
 
 		void listbox::disable_single(bool for_selection)
 		{
+			internal_scope_guard lock;
 			_m_ess().lister.disable_single(for_selection);
 		}
 
+		bool listbox::is_single_enabled(bool for_selection) const noexcept
+		{
+			internal_scope_guard lock;
+			return _m_ess().lister.is_single_enabled(for_selection);
+		}
+
         listbox::export_options& listbox::def_export_options()
         {
 			return _m_ess().def_exp_options;