diff --git a/core/block.js b/core/block.js
index 0f610c2e7..f11bc8490 100644
--- a/core/block.js
+++ b/core/block.js
@@ -224,14 +224,14 @@ const Block = function(workspace, prototypeName, opt_id) {
   if (!existingGroup) {
     Events.setGroup(true);
   }
-  const initialUndoFlag = Events.recordUndo;
+  const initialUndoFlag = Events.getRecordUndo();
 
   try {
     // Call an initialization function, if it exists.
     if (typeof this.init == 'function') {
-      Events.recordUndo = false;
+      Events.setRecordUndo(false);
       this.init();
-      Events.recordUndo = initialUndoFlag;
+      Events.setRecordUndo(initialUndoFlag);
     }
 
     // Fire a create event.
@@ -244,7 +244,7 @@ const Block = function(workspace, prototypeName, opt_id) {
       Events.setGroup(false);
     }
     // In case init threw, recordUndo flag should still be reset.
-    Events.recordUndo = initialUndoFlag;
+    Events.setRecordUndo(initialUndoFlag);
   }
 
   // Record initial inline state.
diff --git a/core/events/events.js b/core/events/events.js
index 982e84577..63d8d97f7 100644
--- a/core/events/events.js
+++ b/core/events/events.js
@@ -14,190 +14,274 @@
  * Events fired as a result of actions in Blockly's editor.
  * @namespace Blockly.Events
  */
-goog.provide('Blockly.Events');
+goog.module('Blockly.Events');
+goog.module.declareLegacyNamespace();
 
-goog.require('Blockly.registry');
-goog.require('Blockly.utils');
-
-goog.requireType('Blockly.Block');
-goog.requireType('Blockly.Events.Abstract');
-goog.requireType('Blockly.Workspace');
+/* eslint-disable-next-line no-unused-vars */
+const Abstract = goog.requireType('Blockly.Events.Abstract');
+/* eslint-disable-next-line no-unused-vars */
+const Block = goog.requireType('Blockly.Block');
+/* eslint-disable-next-line no-unused-vars */
+const BlockCreate = goog.requireType('Blockly.Events.BlockCreate');
+/* eslint-disable-next-line no-unused-vars */
+const BlockMove = goog.requireType('Blockly.Events.BlockMove');
+/* eslint-disable-next-line no-unused-vars */
+const CommentCreate = goog.requireType('Blockly.Events.CommentCreate');
+/* eslint-disable-next-line no-unused-vars */
+const CommentMove = goog.requireType('Blockly.Events.CommentMove');
+/* eslint-disable-next-line no-unused-vars */
+const Workspace = goog.requireType('Blockly.Workspace');
+const deprecation = goog.require('Blockly.utils.deprecation');
+const registry = goog.require('Blockly.registry');
+const utils = goog.require('Blockly.utils');
 
 
 /**
  * Group ID for new events.  Grouped events are indivisible.
  * @type {string}
- * @private
  */
-Blockly.Events.group_ = '';
+let group = '';
 
 /**
  * Sets whether the next event should be added to the undo stack.
  * @type {boolean}
  */
-Blockly.Events.recordUndo = true;
+let recordUndo = true;
+/** @deprecated September 2021 */
+exports.recordUndo = recordUndo;
+
+/**
+ * Sets whether events should be added to the undo stack.
+ * @param {boolean} newValue True if events should be added to the undo stack.
+ */
+const setRecordUndo = function(newValue) {
+  recordUndo = newValue;
+};
+exports.setRecordUndo = setRecordUndo;
+
+/**
+ * Returns whether or not events will be added to the undo stack.
+ * @returns {boolean} True if events will be added to the undo stack.
+ */
+const getRecordUndo = function() {
+  return recordUndo;
+};
+exports.getRecordUndo = getRecordUndo;
+
+Object.defineProperties(exports, {
+  recordUndo: {
+    get: function() {
+      deprecation.warn(
+        'Blockly.Events.recordUndo', 'September 2021', 'September 2022',
+        'Blockly.Events.getRecordUndo()');
+      return getRecordUndo();
+    },
+    set: function(record) {
+      deprecation.warn(
+        'Blockly.Events.recordUndo', 'September 2021', 'September 2022',
+        'Blockly.Events.setRecordUndo()');
+      setRecordUndo(record);
+    },
+  }
+ });
 
 /**
  * Allow change events to be created and fired.
  * @type {number}
- * @private
  */
-Blockly.Events.disabled_ = 0;
+let disabled = 0;
+/** @private */
+exports.disabled_ = disabled;
+
+
+Object.defineProperties(exports, {
+  disabled_: {
+    set: function(newValue) {
+      disabled = newValue;
+    },
+  },
+});
 
 /**
  * Name of event that creates a block. Will be deprecated for BLOCK_CREATE.
  * @const
  */
-Blockly.Events.CREATE = 'create';
+const CREATE = 'create';
+exports.CREATE = CREATE;
 
 /**
  * Name of event that creates a block.
  * @const
  */
-Blockly.Events.BLOCK_CREATE = Blockly.Events.CREATE;
+const BLOCK_CREATE = CREATE;
+exports.BLOCK_CREATE = BLOCK_CREATE;
 
 /**
  * Name of event that deletes a block. Will be deprecated for BLOCK_DELETE.
  * @const
  */
-Blockly.Events.DELETE = 'delete';
+const DELETE = 'delete';
+exports.DELETE = DELETE;
 
 /**
  * Name of event that deletes a block.
  * @const
  */
-Blockly.Events.BLOCK_DELETE = Blockly.Events.DELETE;
+const BLOCK_DELETE = DELETE;
+exports.BLOCK_DELETE = BLOCK_DELETE;
 
 /**
  * Name of event that changes a block. Will be deprecated for BLOCK_CHANGE.
  * @const
  */
-Blockly.Events.CHANGE = 'change';
+const CHANGE = 'change';
+exports.CHANGE = CHANGE;
 
 /**
  * Name of event that changes a block.
  * @const
  */
-Blockly.Events.BLOCK_CHANGE = Blockly.Events.CHANGE;
+const BLOCK_CHANGE = CHANGE;
+exports.BLOCK_CHANGE = BLOCK_CHANGE;
 
 /**
  * Name of event that moves a block. Will be deprecated for BLOCK_MOVE.
  * @const
  */
-Blockly.Events.MOVE = 'move';
+const MOVE = 'move';
+exports.MOVE = MOVE;
 
 /**
  * Name of event that moves a block.
  * @const
  */
-Blockly.Events.BLOCK_MOVE = Blockly.Events.MOVE;
+const BLOCK_MOVE = MOVE;
+exports.BLOCK_MOVE = BLOCK_MOVE;
 
 /**
  * Name of event that creates a variable.
  * @const
  */
-Blockly.Events.VAR_CREATE = 'var_create';
+const VAR_CREATE = 'var_create';
+exports.VAR_CREATE = VAR_CREATE;
 
 /**
  * Name of event that deletes a variable.
  * @const
  */
-Blockly.Events.VAR_DELETE = 'var_delete';
+const VAR_DELETE = 'var_delete';
+exports.VAR_DELETE = VAR_DELETE;
 
 /**
  * Name of event that renames a variable.
  * @const
  */
-Blockly.Events.VAR_RENAME = 'var_rename';
+const VAR_RENAME = 'var_rename';
+exports.VAR_RENAME = VAR_RENAME;
 
 /**
  * Name of generic event that records a UI change.
  * @const
  */
-Blockly.Events.UI = 'ui';
+const UI = 'ui';
+exports.UI = UI;
 
 /**
  * Name of event that record a block drags a block.
  * @const
  */
-Blockly.Events.BLOCK_DRAG = 'drag';
+const BLOCK_DRAG = 'drag';
+exports.BLOCK_DRAG = BLOCK_DRAG;
 
 /**
  * Name of event that records a change in selected element.
  * @const
  */
-Blockly.Events.SELECTED = 'selected';
+const SELECTED = 'selected';
+exports.SELECTED = SELECTED;
 
 /**
  * Name of event that records a click.
  * @const
  */
-Blockly.Events.CLICK = 'click';
+const CLICK = 'click';
+exports.CLICK = CLICK;
 
 /**
  * Name of event that records a marker move.
  * @const
  */
-Blockly.Events.MARKER_MOVE = 'marker_move';
+const MARKER_MOVE = 'marker_move';
+exports.MARKER_MOVE = MARKER_MOVE;
 
 /**
  * Name of event that records a bubble open.
  * @const
  */
-Blockly.Events.BUBBLE_OPEN = 'bubble_open';
+const BUBBLE_OPEN = 'bubble_open';
+exports.BUBBLE_OPEN = BUBBLE_OPEN;
 
 /**
  * Name of event that records a trashcan open.
  * @const
  */
-Blockly.Events.TRASHCAN_OPEN = 'trashcan_open';
+const TRASHCAN_OPEN = 'trashcan_open';
+exports.TRASHCAN_OPEN = TRASHCAN_OPEN;
 
 /**
  * Name of event that records a toolbox item select.
  * @const
  */
-Blockly.Events.TOOLBOX_ITEM_SELECT = 'toolbox_item_select';
+const TOOLBOX_ITEM_SELECT = 'toolbox_item_select';
+exports.TOOLBOX_ITEM_SELECT = TOOLBOX_ITEM_SELECT;
 
 /**
  * Name of event that records a theme change.
  * @const
  */
-Blockly.Events.THEME_CHANGE = 'theme_change';
+const THEME_CHANGE = 'theme_change';
+exports.THEME_CHANGE = THEME_CHANGE;
 
 /**
  * Name of event that records a viewport change.
  * @const
  */
-Blockly.Events.VIEWPORT_CHANGE = 'viewport_change';
+const VIEWPORT_CHANGE = 'viewport_change';
+exports.VIEWPORT_CHANGE = VIEWPORT_CHANGE;
 
 /**
  * Name of event that creates a comment.
  * @const
  */
-Blockly.Events.COMMENT_CREATE = 'comment_create';
+const COMMENT_CREATE = 'comment_create';
+exports.COMMENT_CREATE = COMMENT_CREATE;
 
 /**
  * Name of event that deletes a comment.
  * @const
  */
-Blockly.Events.COMMENT_DELETE = 'comment_delete';
+const COMMENT_DELETE = 'comment_delete';
+exports.COMMENT_DELETE = COMMENT_DELETE;
 
 /**
  * Name of event that changes a comment.
  * @const
  */
-Blockly.Events.COMMENT_CHANGE = 'comment_change';
+const COMMENT_CHANGE = 'comment_change';
+exports.COMMENT_CHANGE = COMMENT_CHANGE;
 
 /**
  * Name of event that moves a comment.
  * @const
  */
-Blockly.Events.COMMENT_MOVE = 'comment_move';
+const COMMENT_MOVE = 'comment_move';
+exports.COMMENT_MOVE = COMMENT_MOVE;
 
 /**
  * Name of event that records a workspace load.
  */
-Blockly.Events.FINISHED_LOADING = 'finished_loading';
+const FINISHED_LOADING = 'finished_loading';
+exports.FINISHED_LOADING = FINISHED_LOADING;
 
 /**
  * Type of events that cause objects to be bumped back into the visible
@@ -205,10 +289,11 @@ Blockly.Events.FINISHED_LOADING = 'finished_loading';
  *
  * Not to be confused with bumping so that disconnected connections do not
  * appear connected.
- * @typedef {!Blockly.Events.BlockCreate|!Blockly.Events.BlockMove|
- * !Blockly.Events.CommentCreate|!Blockly.Events.CommentMove}
+ * @typedef {!BlockCreate|!BlockMove|
+ * !CommentCreate|!CommentMove}
  */
-Blockly.Events.BumpEvent;
+let BumpEvent;
+exports.BumpEvent = BumpEvent;
 
 /**
  * List of events that cause objects to be bumped back into the visible
@@ -218,101 +303,99 @@ Blockly.Events.BumpEvent;
  * appear connected.
  * @const
  */
-Blockly.Events.BUMP_EVENTS = [
-  Blockly.Events.BLOCK_CREATE,
-  Blockly.Events.BLOCK_MOVE,
-  Blockly.Events.COMMENT_CREATE,
-  Blockly.Events.COMMENT_MOVE
-];
+const BUMP_EVENTS = [BLOCK_CREATE, BLOCK_MOVE, COMMENT_CREATE, COMMENT_MOVE];
+exports.BUMP_EVENTS = BUMP_EVENTS;
 
 /**
  * List of events queued for firing.
- * @private
  */
-Blockly.Events.FIRE_QUEUE_ = [];
+const FIRE_QUEUE = [];
+/** @private */
+exports.FIRE_QUEUE_ = FIRE_QUEUE;
 
 /**
  * Create a custom event and fire it.
- * @param {!Blockly.Events.Abstract} event Custom data for event.
+ * @param {!Abstract} event Custom data for event.
  */
-Blockly.Events.fire = function(event) {
-  if (!Blockly.Events.isEnabled()) {
+const fire = function(event) {
+  if (!isEnabled()) {
     return;
   }
-  if (!Blockly.Events.FIRE_QUEUE_.length) {
+  if (!FIRE_QUEUE.length) {
     // First event added; schedule a firing of the event queue.
-    setTimeout(Blockly.Events.fireNow_, 0);
+    setTimeout(fireNow, 0);
   }
-  Blockly.Events.FIRE_QUEUE_.push(event);
+  FIRE_QUEUE.push(event);
 };
+exports.fire = fire;
 
 /**
  * Fire all queued events.
- * @private
  */
-Blockly.Events.fireNow_ = function() {
-  var queue = Blockly.Events.filter(Blockly.Events.FIRE_QUEUE_, true);
-  Blockly.Events.FIRE_QUEUE_.length = 0;
-  for (var i = 0, event; (event = queue[i]); i++) {
+const fireNow = function() {
+  const queue = filter(FIRE_QUEUE, true);
+  FIRE_QUEUE.length = 0;
+  for (let i = 0, event; (event = queue[i]); i++) {
     if (!event.workspaceId) {
       continue;
     }
-    var workspace = Blockly.Workspace.getById(event.workspaceId);
-    if (workspace) {
-      workspace.fireChangeListener(event);
+    const Workspace = goog.module.get('Blockly.Workspace');
+    const eventWorkspace = Workspace.getById(event.workspaceId);
+    if (eventWorkspace) {
+      eventWorkspace.fireChangeListener(event);
     }
   }
 };
+/** @private */
+exports.fireNow_ = fireNow;
 
 /**
  * Filter the queued events and merge duplicates.
- * @param {!Array<!Blockly.Events.Abstract>} queueIn Array of events.
+ * @param {!Array<!Abstract>} queueIn Array of events.
  * @param {boolean} forward True if forward (redo), false if backward (undo).
- * @return {!Array<!Blockly.Events.Abstract>} Array of filtered events.
+ * @return {!Array<!Abstract>} Array of filtered events.
  */
-Blockly.Events.filter = function(queueIn, forward) {
-  var queue = queueIn.slice();  // Shallow copy of queue.
+const filter = function(queueIn, forward) {
+  let queue = queueIn.slice();  // Shallow copy of queue.
   if (!forward) {
     // Undo is merged in reverse order.
     queue.reverse();
   }
-  var mergedQueue = [];
-  var hash = Object.create(null);
+  const mergedQueue = [];
+  const hash = Object.create(null);
   // Merge duplicates.
-  for (var i = 0, event; (event = queue[i]); i++) {
+  for (let i = 0, event; (event = queue[i]); i++) {
     if (!event.isNull()) {
       // Treat all UI events as the same type in hash table.
-      var eventType = event.isUiEvent ? Blockly.Events.UI : event.type;
-      var key = [eventType, event.blockId, event.workspaceId].join(' ');
+      const eventType = event.isUiEvent ? UI : event.type;
+      const key = [eventType, event.blockId, event.workspaceId].join(' ');
 
-      var lastEntry = hash[key];
-      var lastEvent = lastEntry ? lastEntry.event : null;
+      const lastEntry = hash[key];
+      const lastEvent = lastEntry ? lastEntry.event : null;
       if (!lastEntry) {
         // Each item in the hash table has the event and the index of that event
         // in the input array.  This lets us make sure we only merge adjacent
         // move events.
-        hash[key] = { event: event, index: i};
+        hash[key] = {event: event, index: i};
         mergedQueue.push(event);
-      } else if (event.type == Blockly.Events.MOVE &&
-          lastEntry.index == i - 1) {
+      } else if (event.type == MOVE && lastEntry.index == i - 1) {
         // Merge move events.
         lastEvent.newParentId = event.newParentId;
         lastEvent.newInputName = event.newInputName;
         lastEvent.newCoordinate = event.newCoordinate;
         lastEntry.index = i;
-      } else if (event.type == Blockly.Events.CHANGE &&
-          event.element == lastEvent.element &&
+      } else if (
+          event.type == CHANGE && event.element == lastEvent.element &&
           event.name == lastEvent.name) {
         // Merge change events.
         lastEvent.newValue = event.newValue;
-      } else if (event.type == Blockly.Events.VIEWPORT_CHANGE) {
+      } else if (event.type == VIEWPORT_CHANGE) {
         // Merge viewport change events.
         lastEvent.viewTop = event.viewTop;
         lastEvent.viewLeft = event.viewLeft;
         lastEvent.scale = event.scale;
         lastEvent.oldScale = event.oldScale;
-      } else if (event.type == Blockly.Events.CLICK &&
-          lastEvent.type == Blockly.Events.BUBBLE_OPEN) {
+      } else if (event.type == CLICK && lastEvent.type == BUBBLE_OPEN) {
         // Drop click events caused by opening/closing bubbles.
       } else {
         // Collision: newer events should merge into this event to maintain
@@ -323,155 +406,168 @@ Blockly.Events.filter = function(queueIn, forward) {
     }
   }
   // Filter out any events that have become null due to merging.
-  queue = mergedQueue.filter(function(e) { return !e.isNull(); });
+  queue = mergedQueue.filter(function(e) {
+    return !e.isNull();
+  });
   if (!forward) {
     // Restore undo order.
     queue.reverse();
   }
   // Move mutation events to the top of the queue.
   // Intentionally skip first event.
-  for (var i = 1, event; (event = queue[i]); i++) {
-    if (event.type == Blockly.Events.CHANGE &&
-        event.element == 'mutation') {
+  for (let i = 1, event; (event = queue[i]); i++) {
+    if (event.type == CHANGE && event.element == 'mutation') {
       queue.unshift(queue.splice(i, 1)[0]);
     }
   }
   return queue;
 };
+exports.filter = filter;
 
 /**
  * Modify pending undo events so that when they are fired they don't land
- * in the undo stack.  Called by Blockly.Workspace.clearUndo.
+ * in the undo stack.  Called by Workspace.clearUndo.
  */
-Blockly.Events.clearPendingUndo = function() {
-  for (var i = 0, event; (event = Blockly.Events.FIRE_QUEUE_[i]); i++) {
+const clearPendingUndo = function() {
+  for (let i = 0, event; (event = FIRE_QUEUE[i]); i++) {
     event.recordUndo = false;
   }
 };
+exports.clearPendingUndo = clearPendingUndo;
 
 /**
  * Stop sending events.  Every call to this function MUST also call enable.
  */
-Blockly.Events.disable = function() {
-  Blockly.Events.disabled_++;
+const disable = function() {
+  disabled++;
 };
+exports.disable = disable;
 
 /**
  * Start sending events.  Unless events were already disabled when the
  * corresponding call to disable was made.
  */
-Blockly.Events.enable = function() {
-  Blockly.Events.disabled_--;
+const enable = function() {
+  disabled--;
 };
+exports.enable = enable;
 
 /**
  * Returns whether events may be fired or not.
  * @return {boolean} True if enabled.
  */
-Blockly.Events.isEnabled = function() {
-  return Blockly.Events.disabled_ == 0;
+const isEnabled = function() {
+  return disabled == 0;
 };
+exports.isEnabled = isEnabled;
 
 /**
  * Current group.
  * @return {string} ID string.
  */
-Blockly.Events.getGroup = function() {
-  return Blockly.Events.group_;
+const getGroup = function() {
+  return group;
 };
+exports.getGroup = getGroup;
 
 /**
  * Start or stop a group.
  * @param {boolean|string} state True to start new group, false to end group.
  *   String to set group explicitly.
  */
-Blockly.Events.setGroup = function(state) {
+const setGroup = function(state) {
   if (typeof state == 'boolean') {
-    Blockly.Events.group_ = state ? Blockly.utils.genUid() : '';
+    group = state ? utils.genUid() : '';
   } else {
-    Blockly.Events.group_ = state;
+    group = state;
   }
 };
+exports.setGroup = setGroup;
 
 /**
  * Compute a list of the IDs of the specified block and all its descendants.
- * @param {!Blockly.Block} block The root block.
+ * @param {!Block} block The root block.
  * @return {!Array<string>} List of block IDs.
- * @package
  */
-Blockly.Events.getDescendantIds = function(block) {
-  var ids = [];
-  var descendants = block.getDescendants(false);
-  for (var i = 0, descendant; (descendant = descendants[i]); i++) {
+const getDescendantIds = function(block) {
+  const ids = [];
+  const descendants = block.getDescendants(false);
+  for (let i = 0, descendant; (descendant = descendants[i]); i++) {
     ids[i] = descendant.id;
   }
   return ids;
 };
+/** @package */
+exports.getDescendantIds = getDescendantIds;
 
 /**
  * Decode the JSON into an event.
  * @param {!Object} json JSON representation.
- * @param {!Blockly.Workspace} workspace Target workspace for event.
- * @return {!Blockly.Events.Abstract} The event represented by the JSON.
+ * @param {!Workspace} workspace Target workspace for event.
+ * @return {!Abstract} The event represented by the JSON.
  * @throws {Error} if an event type is not found in the registry.
  */
-Blockly.Events.fromJson = function(json, workspace) {
-  var eventClass = Blockly.Events.get(json.type);
+const fromJson = function(json, workspace) {
+  const eventClass = get(json.type);
   if (!eventClass) {
     throw Error('Unknown event type.');
   }
-  var event = new eventClass();
+  const event = new eventClass();
   event.fromJson(json);
   event.workspaceId = workspace.id;
   return event;
 };
+exports.fromJson = fromJson;
 
 /**
  * Gets the class for a specific event type from the registry.
  * @param {string} eventType The type of the event to get.
- * @return {?function(new:Blockly.Events.Abstract, ...?)} The event class with
+ * @return {?function(new:Abstract, ...?)} The event class with
  *     the given type or null if none exists.
  */
-Blockly.Events.get = function(eventType) {
-  return Blockly.registry.getClass(Blockly.registry.Type.EVENT, eventType);
+const get = function(eventType) {
+  return registry.getClass(registry.Type.EVENT, eventType);
 };
+exports.get = get;
 
 /**
  * Enable/disable a block depending on whether it is properly connected.
  * Use this on applications where all blocks should be connected to a top block.
  * Recommend setting the 'disable' option to 'false' in the config so that
  * users don't try to re-enable disabled orphan blocks.
- * @param {!Blockly.Events.Abstract} event Custom data for event.
+ * @param {!Abstract} event Custom data for event.
  */
-Blockly.Events.disableOrphans = function(event) {
-  if (event.type == Blockly.Events.MOVE ||
-      event.type == Blockly.Events.CREATE) {
+const disableOrphans = function(event) {
+  if (event.type == MOVE || event.type == CREATE) {
     if (!event.workspaceId) {
       return;
     }
-    var workspace = Blockly.Workspace.getById(event.workspaceId);
-    var block = workspace.getBlockById(event.blockId);
+    const Workspace = goog.module.get('Blockly.Workspace');
+    const eventWorkspace = Workspace.getById(event.workspaceId);
+    let block = eventWorkspace.getBlockById(event.blockId);
     if (block) {
       // Changing blocks as part of this event shouldn't be undoable.
-      var initialUndoFlag = Blockly.Events.recordUndo;
+      const initialUndoFlag = recordUndo;
       try {
-        Blockly.Events.recordUndo = false;
-        var parent = block.getParent();
+        recordUndo = false;
+        const parent = block.getParent();
         if (parent && parent.isEnabled()) {
-          var children = block.getDescendants(false);
-          for (var i = 0, child; (child = children[i]); i++) {
+          const children = block.getDescendants(false);
+          for (let i = 0, child; (child = children[i]); i++) {
             child.setEnabled(true);
           }
-        } else if ((block.outputConnection || block.previousConnection) &&
-                  !workspace.isDragging()) {
+        } else if (
+            (block.outputConnection || block.previousConnection) &&
+            !eventWorkspace.isDragging()) {
           do {
             block.setEnabled(false);
             block = block.getNextBlock();
           } while (block);
         }
       } finally {
-        Blockly.Events.recordUndo = initialUndoFlag;
+        recordUndo = initialUndoFlag;
       }
     }
   }
 };
+exports.disableOrphans = disableOrphans;
diff --git a/core/events/events_abstract.js b/core/events/events_abstract.js
index 9a14e82b2..eff43fdac 100644
--- a/core/events/events_abstract.js
+++ b/core/events/events_abstract.js
@@ -48,7 +48,7 @@ const Abstract = function() {
    * Sets whether the event should be added to the undo stack.
    * @type {boolean}
    */
-  this.recordUndo = Events.recordUndo;
+  this.recordUndo = Events.getRecordUndo();
 };
 
 /**
diff --git a/core/events/events_comment_base.js b/core/events/events_comment_base.js
index 70b81e056..59880d3db 100644
--- a/core/events/events_comment_base.js
+++ b/core/events/events_comment_base.js
@@ -60,7 +60,7 @@ const CommentBase = function(opt_comment) {
    * Sets whether the event should be added to the undo stack.
    * @type {boolean}
    */
-  this.recordUndo = Events.recordUndo;
+  this.recordUndo = Events.getRecordUndo();
 };
 object.inherits(CommentBase, AbstractEvents);
 
diff --git a/core/procedures.js b/core/procedures.js
index e63618e7c..57a18b5dd 100644
--- a/core/procedures.js
+++ b/core/procedures.js
@@ -362,7 +362,7 @@ exports.getCallers = getCallers;
  * @param {!Block} defBlock Procedure definition block.
  */
 const mutateCallers = function(defBlock) {
-  const oldRecordUndo = Events.recordUndo;
+  const oldRecordUndo = Events.getRecordUndo();
   const procedureBlock = /** @type {!ProcedureBlock} */ (defBlock);
   const name = procedureBlock.getProcedureDef()[0];
   const xmlElement = defBlock.mutationToDom(true);
@@ -377,10 +377,10 @@ const mutateCallers = function(defBlock) {
       // Fire a mutation on every caller block.  But don't record this as an
       // undo action since it is deterministically tied to the procedure's
       // definition mutation.
-      Events.recordUndo = false;
+      Events.setRecordUndo(false);
       Events.fire(new (Events.get(Events.BLOCK_CHANGE))(
           caller, 'mutation', null, oldMutation, newMutation));
-      Events.recordUndo = oldRecordUndo;
+      Events.setRecordUndo(oldRecordUndo);
     }
   }
 };
diff --git a/core/rendered_connection.js b/core/rendered_connection.js
index 0abc123e5..39dee432c 100644
--- a/core/rendered_connection.js
+++ b/core/rendered_connection.js
@@ -458,7 +458,7 @@ RenderedConnection.prototype.isConnectionAllowed = function(
  */
 RenderedConnection.prototype.onFailedConnect = function(otherConnection) {
   const block = this.getSourceBlock();
-  if (Events.recordUndo) {
+  if (Events.getRecordUndo()) {
     const group = Events.getGroup();
     setTimeout(function() {
       if (!block.isDisposed() && !block.getParent()) {
diff --git a/core/workspace.js b/core/workspace.js
index 77b50967e..f1acb4aec 100644
--- a/core/workspace.js
+++ b/core/workspace.js
@@ -633,14 +633,14 @@ Workspace.prototype.undo = function(redo) {
     outputStack.push(event);
   }
   events = Events.filter(events, redo);
-  Events.recordUndo = false;
+  Events.setRecordUndo(false);
   try {
     for (let i = 0; i < events.length; i++) {
       const event = events[i];
       event.run(redo);
     }
   } finally {
-    Events.recordUndo = true;
+    Events.setRecordUndo(true);
   }
 };
 
diff --git a/core/xml.js b/core/xml.js
index 661631d27..7406e0e09 100644
--- a/core/xml.js
+++ b/core/xml.js
@@ -25,6 +25,8 @@ const Size = goog.require('Blockly.utils.Size');
 const VariableModel = goog.requireType('Blockly.VariableModel');
 /* eslint-disable-next-line no-unused-vars */
 const Workspace = goog.requireType('Blockly.Workspace');
+/* eslint-disable-next-line no-unused-vars */
+const WorkspaceSvg = goog.requireType('Blockly.WorkspaceSvg');
 const dom = goog.require('Blockly.utils.dom');
 const inputTypes = goog.require('Blockly.inputTypes');
 const utilsXml = goog.require('Blockly.utils.xml');
@@ -433,11 +435,10 @@ const domToWorkspace = function(xml, workspace) {
   }
   let variablesFirst = true;
   try {
-    for (let i = 0; i < xml.childNodes.length; i++) {
-      const xmlChild = xml.childNodes[i];
+    for (let i = 0, xmlChild; (xmlChild = xml.childNodes[i]); i++) {
       const name = xmlChild.nodeName.toLowerCase();
       const xmlChildElement = /** @type {!Element} */ (xmlChild);
-      if (name == 'block' || (name == 'shadow' && !Events.recordUndo)) {
+      if (name == 'block' || (name == 'shadow' && !Events.getRecordUndo())) {
         // Allow top-level shadow blocks if recordUndo is disabled since
         // that means an undo is in progress.  Such a block is expected
         // to be moved to a nested destination in the next operation.
@@ -466,7 +467,7 @@ const domToWorkspace = function(xml, workspace) {
           } else {
             WorkspaceCommentSvg.fromXml(
                 xmlChildElement,
-                /** @type {!Blockly.WorkspaceSvg} */ (workspace), width);
+                /** @type {!WorkspaceSvg} */ (workspace), width);
           }
         } else {
           const WorkspaceComment = goog.module.get('Blockly.WorkspaceComment');
diff --git a/tests/deps.js b/tests/deps.js
index 2ec43e967..41eb31f3d 100644
--- a/tests/deps.js
+++ b/tests/deps.js
@@ -34,7 +34,7 @@ goog.addDependency('../../core/css.js', ['Blockly.Css'], [], {'lang': 'es6', 'mo
 goog.addDependency('../../core/delete_area.js', ['Blockly.DeleteArea'], ['Blockly.BlockSvg', 'Blockly.DragTarget', 'Blockly.utils.object'], {'lang': 'es6', 'module': 'goog'});
 goog.addDependency('../../core/drag_target.js', ['Blockly.DragTarget'], [], {'lang': 'es6', 'module': 'goog'});
 goog.addDependency('../../core/dropdowndiv.js', ['Blockly.DropDownDiv'], ['Blockly.common', 'Blockly.utils.Rect', 'Blockly.utils.dom', 'Blockly.utils.math', 'Blockly.utils.style'], {'lang': 'es6', 'module': 'goog'});
-goog.addDependency('../../core/events/events.js', ['Blockly.Events'], ['Blockly.registry', 'Blockly.utils']);
+goog.addDependency('../../core/events/events.js', ['Blockly.Events'], ['Blockly.registry', 'Blockly.utils', 'Blockly.utils.deprecation'], {'lang': 'es6', 'module': 'goog'});
 goog.addDependency('../../core/events/events_abstract.js', ['Blockly.Events.Abstract'], ['Blockly.Events'], {'lang': 'es6', 'module': 'goog'});
 goog.addDependency('../../core/events/events_block_base.js', ['Blockly.Events.BlockBase'], ['Blockly.Events.Abstract', 'Blockly.utils.object'], {'lang': 'es6', 'module': 'goog'});
 goog.addDependency('../../core/events/events_block_change.js', ['Blockly.Events.BlockChange'], ['Blockly.Events', 'Blockly.Xml', 'Blockly.registry', 'Blockly.utils.object'], {'lang': 'es6', 'module': 'goog'});