diff --git a/HISTORY.md b/HISTORY.md
index fe22be1e..79141153 100755
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -5,7 +5,6 @@
 * **New Features:**
     * new "reshape" primitive for lists
     * list operations as dropdown menu of new "length of list" block
-    * experimental list slice() primitive, hidden, available via find / relabel
 * **Notable Changes:**
     * 2D lists inside ITEM OF now have the right order of dimensions (rows, columns, planes, etc.)
     * changed "length of list" to become a general list operations primitive
@@ -24,6 +23,9 @@
 * **Translation Updates:**
     * German
 
+### 2021-02-23
+* threads, objects: commented out experimental slice() primitive
+
 ### 2021-02-20
 * lists: removed experimental list.slice() feature from production code
 * threads, objects: experimental list slice() primitive, hidden, available via find / relabel
diff --git a/snap.html b/snap.html
index 4572724a..510e41bf 100755
--- a/snap.html
+++ b/snap.html
@@ -9,8 +9,8 @@
         <script src="src/symbols.js?version=2020-10-07"></script>
         <script src="src/widgets.js?version=2021-01-05"></script>
         <script src="src/blocks.js?version=2021-02-15"></script>
-        <script src="src/threads.js?version=2021-02-20"></script>
-        <script src="src/objects.js?version=2021-02-20"></script>
+        <script src="src/threads.js?version=2021-02-23"></script>
+        <script src="src/objects.js?version=2021-02-23"></script>
         <script src="src/gui.js?version=2021-02-04"></script>
         <script src="src/paint.js?version=2020-05-17"></script>
         <script src="src/lists.js?version=2021-02-20"></script>
diff --git a/src/objects.js b/src/objects.js
index c758cd47..d621ff6d 100644
--- a/src/objects.js
+++ b/src/objects.js
@@ -84,7 +84,7 @@ BlockEditorMorph, BlockDialogMorph, PrototypeHatBlockMorph,  BooleanSlotMorph,
 localize, TableMorph, TableFrameMorph, normalizeCanvas, VectorPaintEditorMorph,
 AlignmentMorph, Process, WorldMap, copyCanvas, useBlurredShadows*/
 
-modules.objects = '2021-February-20';
+modules.objects = '2021-February-23';
 
 var SpriteMorph;
 var StageMorph;
@@ -1409,12 +1409,14 @@ SpriteMorph.prototype.initBlocks = function () {
             spec: 'reshape %l to %nums',
             defaults: [null, [4, 3]]
         },
-        reportSlice: {
+    /*
+        reportSlice: { // currently not in use
             type: 'reporter',
             category: 'lists',
             spec: 'slice %l by %nums',
             defaults: [null, [2, -1]]
         },
+    */
 
         // HOFs
         reportMap: {
@@ -1762,10 +1764,6 @@ SpriteMorph.prototype.blockAlternatives = {
     doShowVar: ['doHideVar'],
     doHideVar: ['doShowVar'],
 
-    // lists:
-    reportReshape: ['reportSlice'],
-    reportSlice: ['reportReshape'],
-
     // HOFs
     reportMap: ['reportKeep', 'reportFindFirst'],
     reportKeep: ['reportFindFirst', 'reportMap'],
diff --git a/src/threads.js b/src/threads.js
index 1a97b8cd..a06ac827 100644
--- a/src/threads.js
+++ b/src/threads.js
@@ -61,7 +61,7 @@ StageMorph, SpriteMorph, StagePrompterMorph, Note, modules, isString, copy, Map,
 isNil, WatcherMorph, List, ListWatcherMorph, alert, console, TableMorph, BLACK,
 TableFrameMorph, ColorSlotMorph, isSnapObject, newCanvas, Symbol, SVG_Costume*/
 
-modules.threads = '2021-February-20';
+modules.threads = '2021-February-23';
 
 var ThreadManager;
 var Process;
@@ -1971,6 +1971,7 @@ Process.prototype.reportReshape = function (list, shape) {
 };
 
 Process.prototype.reportSlice = function (list, indices) {
+    // currently not in use
     this.assertType(list, 'list');
     this.assertType(indices, 'list');
     return list.slice(indices);