diff --git a/HISTORY.md b/HISTORY.md
index 9fe406a1..8996d4f6 100755
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -11,6 +11,7 @@
     * new MOUSE POSITION primitive reporter in the SENSING category
     * new "position" choice in OF reporter's attribute dropdown, reports a list of XY coordinates
     * new "categories" choice in MY reporter's dropdown, reports an ordered list of all category names whose indices match the "category" reported elsewhere
+    * new localization extension primitives (prefixed "loc_")
     * new "Tad" costume series, thanks, Meghan and Brian!
 * **Notable Changes:**
     * exporting a library includes dependencies (auto-select all referenced blocks)
@@ -36,7 +37,8 @@
 * extensions: added new extension primitive "loc_translate(text)"
 * extensions: added more extension translation primitives, under construction
 * objects: tweaked ASK menu display distinction for FALSE Booleans
-* extensions: tweaked localization extension prims, under construction 
+* extensions: tweaked localization extension prims, under construction
+* extensions, gui: added new extension prims (done)
 
 ### 2022-04-03
 * objects: added shortcut support for ASK menu items
diff --git a/snap.html b/snap.html
index a7aa671c..28b31a61 100755
--- a/snap.html
+++ b/snap.html
@@ -20,7 +20,7 @@
         <script src="src/threads.js?version=2022-03-31"></script>
         <script src="src/objects.js?version=2022-04-04"></script>
         <script src="src/scenes.js?version=2022-03-03"></script>
-        <script src="src/gui.js?version=2022-03-17"></script>
+        <script src="src/gui.js?version=2022-04-04"></script>
         <script src="src/paint.js?version=2021-07-05"></script>
         <script src="src/lists.js?version=2022-02-07"></script>
         <script src="src/byob.js?version=2022-03-23"></script>
diff --git a/src/extensions.js b/src/extensions.js
index 55b1efe8..b9afd05c 100644
--- a/src/extensions.js
+++ b/src/extensions.js
@@ -29,7 +29,7 @@
 
 /*global modules, List, StageMorph, Costume, SpeechSynthesisUtterance, Sound,
 IDE_Morph, CamSnapshotDialogMorph, SoundRecorderDialogMorph, isSnapObject, nop,
-Color, Process, contains, localize, SnapTranslator*/
+Color, Process, contains, localize, SnapTranslator, isString*/
 
 /*jshint esversion: 11, bitwise: false*/
 
@@ -806,16 +806,19 @@ SnapExtensions.primitives.set(
     }
 );
 
-/*
 SnapExtensions.primitives.set(
     'loc_set(language, [msg])',
     function (lang, msg, proc) {
-        if (arguments.length === 1) {
-            return SnapTranslator.language;
+        var ide = this.parentThatIsA(IDE_Morph),
+            disabled = ['receiveGo', 'receiveCondition', 'receiveMessage'],
+            callback = null;
+        ide.loadNewProject = false;
+        if (isString(msg) && !contains(disabled, proc.topBlock.selector)) {
+            callback = () => ide.broadcast(msg);
         }
+        ide.setLanguage(lang, callback, true, true); // don't save, delay
     }
 );
-*/
 
 SnapExtensions.primitives.set(
     'loc_translations()',
diff --git a/src/gui.js b/src/gui.js
index 0d311c49..63550a12 100644
--- a/src/gui.js
+++ b/src/gui.js
@@ -86,7 +86,7 @@ BlockVisibilityDialogMorph, ThreadManager*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.gui = '2022-March-18';
+modules.gui = '2022-April-04';
 
 // Declarations
 
@@ -6611,7 +6611,7 @@ IDE_Morph.prototype.languageMenu = function () {
     menu.popup(world, pos);
 };
 
-IDE_Morph.prototype.setLanguage = function (lang, callback, noSave) {
+IDE_Morph.prototype.setLanguage = function (lang, callback, noSave, delay) {
     var translation = document.getElementById('language'),
         src = this.resourceURL('locale', 'lang-' + lang + '.js');
     SnapTranslator.unload();
@@ -6619,16 +6619,17 @@ IDE_Morph.prototype.setLanguage = function (lang, callback, noSave) {
         document.head.removeChild(translation);
     }
     if (lang === 'en') {
-        return this.reflectLanguage('en', callback, noSave);
+        return this.reflectLanguage('en', callback, noSave, delay);
     }
     translation = document.createElement('script');
     translation.id = 'language';
-    translation.onload = () => this.reflectLanguage(lang, callback, noSave);
+    translation.onload = () =>
+        this.reflectLanguage(lang, callback, noSave, delay);
     document.head.appendChild(translation);
     translation.src = src;
 };
 
-IDE_Morph.prototype.reflectLanguage = function (lang, callback, noSave) {
+IDE_Morph.prototype.reflectLanguage = function (lang, callback, noSave, delay) {
     var projectData,
         urlBar = location.hash;
     SnapTranslator.language = lang;
@@ -6658,12 +6659,12 @@ IDE_Morph.prototype.reflectLanguage = function (lang, callback, noSave) {
         this.newProject();
         location.hash = urlBar;
     } else {
-        this.openProjectString(projectData);
+        this.openProjectString(projectData, delay ? callback : null);
     }
     if (!noSave) {
         this.saveSetting('language', lang);
     }
-    if (callback) {callback.call(this); }
+    if (callback && !delay) {callback.call(this); }
 };
 
 // IDE_Morph blocks scaling