diff --git a/core/events/events_var_base.js b/core/events/events_var_base.js
index f4de12429..cedf349b7 100644
--- a/core/events/events_var_base.js
+++ b/core/events/events_var_base.js
@@ -13,17 +13,17 @@
 goog.module('Blockly.Events.VarBase');
 goog.module.declareLegacyNamespace();
 
-goog.require('Blockly.Events.Abstract');
-goog.require('Blockly.utils.object');
-
-goog.requireType('Blockly.VariableModel');
+const Abstract = goog.require('Blockly.Events.Abstract');
+/* eslint-disable-next-line no-unused-vars */
+const VariableModel = goog.requireType('Blockly.VariableModel');
+const object = goog.require('Blockly.utils.object');
 
 
 /**
  * Abstract class for a variable event.
- * @param {!Blockly.VariableModel=} opt_variable The variable this event
+ * @param {!VariableModel=} opt_variable The variable this event
  *     corresponds to.  Undefined for a blank event.
- * @extends {Blockly.Events.Abstract}
+ * @extends {Abstract}
  * @constructor
  */
 const VarBase = function(opt_variable) {
@@ -42,7 +42,7 @@ const VarBase = function(opt_variable) {
    */
   this.workspaceId = this.isBlank ? '' : opt_variable.workspace.id;
 };
-Blockly.utils.object.inherits(VarBase, Blockly.Events.Abstract);
+object.inherits(VarBase, Abstract);
 
 /**
  * Encode the event as JSON.
diff --git a/core/events/events_var_create.js b/core/events/events_var_create.js
index 3fd79d64c..1d5c3ca75 100644
--- a/core/events/events_var_create.js
+++ b/core/events/events_var_create.js
@@ -13,19 +13,19 @@
 goog.module('Blockly.Events.VarCreate');
 goog.module.declareLegacyNamespace();
 
-goog.require('Blockly.Events');
-goog.require('Blockly.Events.VarBase');
-goog.require('Blockly.registry');
-goog.require('Blockly.utils.object');
-
-goog.requireType('Blockly.VariableModel');
+const Events = goog.require('Blockly.Events');
+const VarBase = goog.require('Blockly.Events.VarBase');
+/* eslint-disable-next-line no-unused-vars */
+const VariableModel = goog.requireType('Blockly.VariableModel');
+const object = goog.require('Blockly.utils.object');
+const registry = goog.require('Blockly.registry');
 
 
 /**
  * Class for a variable creation event.
- * @param {!Blockly.VariableModel=} opt_variable The created variable. Undefined
+ * @param {!VariableModel=} opt_variable The created variable. Undefined
  *     for a blank event.
- * @extends {Blockly.Events.VarBase}
+ * @extends {VarBase}
  * @constructor
  */
 const VarCreate = function(opt_variable) {
@@ -37,13 +37,13 @@ const VarCreate = function(opt_variable) {
   this.varType = opt_variable.type;
   this.varName = opt_variable.name;
 };
-Blockly.utils.object.inherits(VarCreate, Blockly.Events.VarBase);
+object.inherits(VarCreate, VarBase);
 
 /**
  * Type of this event.
  * @type {string}
  */
-VarCreate.prototype.type = Blockly.Events.VAR_CREATE;
+VarCreate.prototype.type = Events.VAR_CREATE;
 
 /**
  * Encode the event as JSON.
@@ -79,7 +79,7 @@ VarCreate.prototype.run = function(forward) {
   }
 };
 
-Blockly.registry.register(Blockly.registry.Type.EVENT,
-    Blockly.Events.VAR_CREATE, VarCreate);
+registry.register(registry.Type.EVENT,
+    Events.VAR_CREATE, VarCreate);
 
 exports = VarCreate;
diff --git a/core/events/events_var_delete.js b/core/events/events_var_delete.js
index fa2af41a6..cd93ccf39 100644
--- a/core/events/events_var_delete.js
+++ b/core/events/events_var_delete.js
@@ -13,19 +13,19 @@
 goog.module('Blockly.Events.VarDelete');
 goog.module.declareLegacyNamespace();
 
-goog.require('Blockly.Events');
-goog.require('Blockly.Events.VarBase');
-goog.require('Blockly.registry');
-goog.require('Blockly.utils.object');
-
-goog.requireType('Blockly.VariableModel');
+const Events = goog.require('Blockly.Events');
+const VarBase = goog.require('Blockly.Events.VarBase');
+/* eslint-disable-next-line no-unused-vars */
+const VariableModel = goog.requireType('Blockly.VariableModel');
+const object = goog.require('Blockly.utils.object');
+const registry = goog.require('Blockly.registry');
 
 
 /**
  * Class for a variable deletion event.
- * @param {!Blockly.VariableModel=} opt_variable The deleted variable. Undefined
+ * @param {!VariableModel=} opt_variable The deleted variable. Undefined
  *     for a blank event.
- * @extends {Blockly.Events.VarBase}
+ * @extends {VarBase}
  * @constructor
  */
 const VarDelete = function(opt_variable) {
@@ -37,13 +37,13 @@ const VarDelete = function(opt_variable) {
   this.varType = opt_variable.type;
   this.varName = opt_variable.name;
 };
-Blockly.utils.object.inherits(VarDelete, Blockly.Events.VarBase);
+object.inherits(VarDelete, VarBase);
 
 /**
  * Type of this event.
  * @type {string}
  */
-VarDelete.prototype.type = Blockly.Events.VAR_DELETE;
+VarDelete.prototype.type = Events.VAR_DELETE;
 
 /**
  * Encode the event as JSON.
@@ -79,7 +79,7 @@ VarDelete.prototype.run = function(forward) {
   }
 };
 
-Blockly.registry.register(Blockly.registry.Type.EVENT,
-    Blockly.Events.VAR_DELETE, VarDelete);
+registry.register(registry.Type.EVENT,
+    Events.VAR_DELETE, VarDelete);
 
 exports = VarDelete;
diff --git a/core/events/events_var_rename.js b/core/events/events_var_rename.js
index 418164167..1f7d0b982 100644
--- a/core/events/events_var_rename.js
+++ b/core/events/events_var_rename.js
@@ -13,20 +13,20 @@
 goog.module('Blockly.Events.VarRename');
 goog.module.declareLegacyNamespace();
 
-goog.require('Blockly.Events');
-goog.require('Blockly.Events.VarBase');
-goog.require('Blockly.registry');
-goog.require('Blockly.utils.object');
-
-goog.requireType('Blockly.VariableModel');
+const Events = goog.require('Blockly.Events');
+const VarBase = goog.require('Blockly.Events.VarBase');
+/* eslint-disable-next-line no-unused-vars */
+const VariableModel = goog.requireType('Blockly.VariableModel');
+const object = goog.require('Blockly.utils.object');
+const registry = goog.require('Blockly.registry');
 
 
 /**
  * Class for a variable rename event.
- * @param {!Blockly.VariableModel=} opt_variable The renamed variable. Undefined
+ * @param {!VariableModel=} opt_variable The renamed variable. Undefined
  *     for a blank event.
  * @param {string=} newName The new name the variable will be changed to.
- * @extends {Blockly.Events.VarBase}
+ * @extends {VarBase}
  * @constructor
  */
 const VarRename = function(opt_variable, newName) {
@@ -38,13 +38,13 @@ const VarRename = function(opt_variable, newName) {
   this.oldName = opt_variable.name;
   this.newName = typeof newName == 'undefined' ? '' : newName;
 };
-Blockly.utils.object.inherits(VarRename, Blockly.Events.VarBase);
+object.inherits(VarRename, VarBase);
 
 /**
  * Type of this event.
  * @type {string}
  */
-VarRename.prototype.type = Blockly.Events.VAR_RENAME;
+VarRename.prototype.type = Events.VAR_RENAME;
 
 /**
  * Encode the event as JSON.
@@ -80,7 +80,7 @@ VarRename.prototype.run = function(forward) {
   }
 };
 
-Blockly.registry.register(Blockly.registry.Type.EVENT,
-    Blockly.Events.VAR_RENAME, VarRename);
+registry.register(registry.Type.EVENT,
+    Events.VAR_RENAME, VarRename);
 
 exports = VarRename;