diff --git a/RELEASE_NOTES b/RELEASE_NOTES
index ae94f7c6412..c7ae8cfe4af 100644
--- a/RELEASE_NOTES
+++ b/RELEASE_NOTES
@@ -10,3 +10,8 @@ is making sure that spelling/grammer/whatever is usable and that you are using
 
 The release team should empty this file after each release.
 
+
+There is a new experimental function to gray out not available languages in the
+language selection dialog. This feature is available when Wesnoth is started
+with the --new-widgets parameter. Packagers of various platforms are encouraged
+to test this feature and report bugs when found. 
diff --git a/changelog b/changelog
index 18f6b07a7ac..5de24a1efbc 100644
--- a/changelog
+++ b/changelog
@@ -17,10 +17,14 @@ Version 1.5.0+svn:
  * graphics:
    * new ford graphics from Syntax_Error
    * added a sea serpent portrait by Pic
+   * various improvements to the new widget library
  * language and i18n:
    * new translations: Friulian, Macedonian
    * updated translations: Chinese, Czech, Danish, Finnish, French, German, Italian,
      Polish, Russian, Slovak, Spanish, Turkish
+   * the new widget library supports disabling of rows in a listbox, this is
+     used to deactivate not available languages. This feature is experimental
+     and only available when started with --new-widgets (bug #11212)
  * multiplayer:
    * revised maps: Den of Onis
  * Python AI:
diff --git a/src/gui/dialogs/language_selection.cpp b/src/gui/dialogs/language_selection.cpp
index f5a404e9620..c93dc825a1e 100644
--- a/src/gui/dialogs/language_selection.cpp
+++ b/src/gui/dialogs/language_selection.cpp
@@ -51,6 +51,8 @@ void tlanguage_selection::show(CVideo& video)
 			std::cerr << "select row " << list->get_item_count() - 1 << ".\n";
 			list->select_row(list->get_item_count() - 1);
 		}
+
+		list->set_row_active(list->get_item_count() - 1, lang.available());
 	}
 
 	window.recalculate_size();
diff --git a/src/language.cpp b/src/language.cpp
index 64b8bfc76e5..68bfd64f8aa 100644
--- a/src/language.cpp
+++ b/src/language.cpp
@@ -17,6 +17,7 @@
 
 #include "config.hpp"
 #include "filesystem.hpp"
+#include "foreach.hpp"
 #include "game_config.hpp"
 #include "gettext.hpp"
 #include "language.hpp"
@@ -35,6 +36,41 @@
 #include <cstdlib>
 #include <cstring>
 #include <iostream>
+#include <stdexcept>
+
+/** Tests one locale to be available. */
+static bool has_locale(const char* s) {
+	try {
+		// The way to find out whether a locale is available is to set it and
+		// hope not runtime error gets thrown.
+		std::locale dummy(s);
+		std::cerr << "Locale : " << s << " found.\n";
+		return true;
+	} catch (std::runtime_error&) {
+		std::cerr << "Locale : " << s << " not found.\n";
+		return false;
+	}
+}		
+
+/** Test the locale for a language and it's utf-8 variations. */
+static bool has_language(const std::string& language)
+{
+	if(has_locale(language.c_str())) {
+		return true;
+	}
+
+	std::string utf = language + ".utf-8";
+	if(has_locale(utf.c_str())) {
+		return true;
+	}
+
+	utf = language + ".UTF-8";
+	if(has_locale(utf.c_str())) {
+		return true;
+	}
+	
+	return false;
+}
 
 namespace {
 	language_def current_language;
@@ -58,6 +94,25 @@ bool language_def::operator== (const language_def& a) const
 	return ((language == a.language) /* && (localename == a.localename) */ );
 }
 
+bool language_def::available() const
+{
+#ifdef USE_DUMMYLOCALES
+	// Dummy has every language available.
+	return true;
+#else
+	if(has_language(localename)) {
+		return true;
+	} else {
+		foreach(const std::string& lang, alternates) {
+			if(has_language(lang)) {
+				return true;
+			}
+		}
+	}
+	return false;
+#endif
+}
+
 symbol_table string_table;
 
 const t_string& symbol_table::operator[](const std::string& key) const
diff --git a/src/language.hpp b/src/language.hpp
index 1275deae4a1..0a89c68aaed 100644
--- a/src/language.hpp
+++ b/src/language.hpp
@@ -50,6 +50,13 @@ struct language_def
 	t_string language;
 	bool rtl;		// A right to left language? (e.g: Hebrew)
 	bool operator== (const language_def&) const;
+	
+	/**
+	 * Is the locale available on the system?
+	 *
+	 * If the dummy locales are selected we always return true.
+	 */
+	bool available() const;
 };
 
 std::string languagedef_name (const language_def& def);