diff --git a/core/events/events_var_create.ts b/core/events/events_var_create.ts
index 63292bc84..eb8ccfe9f 100644
--- a/core/events/events_var_create.ts
+++ b/core/events/events_var_create.ts
@@ -53,7 +53,7 @@ export class VarCreate extends VarBase {
    */
   override toJson(): VarCreateJson {
     const json = super.toJson() as VarCreateJson;
-    if (!this.varType) {
+    if (this.varType === undefined) {
       throw new Error(
           'The var type is undefined. Either pass a variable to ' +
           'the constructor, or call fromJson');
diff --git a/core/events/events_var_delete.ts b/core/events/events_var_delete.ts
index d3f6c6f4f..be0fec4fe 100644
--- a/core/events/events_var_delete.ts
+++ b/core/events/events_var_delete.ts
@@ -48,7 +48,7 @@ export class VarDelete extends VarBase {
    */
   override toJson(): VarDeleteJson {
     const json = super.toJson() as VarDeleteJson;
-    if (!this.varType) {
+    if (this.varType === undefined) {
       throw new Error(
           'The var type is undefined. Either pass a variable to ' +
           'the constructor, or call fromJson');
diff --git a/tests/mocha/event_var_create_test.js b/tests/mocha/event_var_create_test.js
index b90372e8f..dbcd7a4ab 100644
--- a/tests/mocha/event_var_create_test.js
+++ b/tests/mocha/event_var_create_test.js
@@ -21,7 +21,18 @@ suite('Var Create Event', function() {
   });
 
   suite('Serialization', function() {
-    test('events round-trip through JSON', function() {
+    test('untyped variable events round-trip through JSON', function() {
+      const varModel =
+          new Blockly.VariableModel(this.workspace, 'name', '', 'id');
+      const origEvent = new Blockly.Events.VarCreate(varModel);
+
+      const json = origEvent.toJson();
+      const newEvent = new Blockly.Events.fromJson(json, this.workspace);
+
+      chai.assert.deepEqual(newEvent, origEvent);
+    });
+
+    test('typed variable events round-trip through JSON', function() {
       const varModel =
           new Blockly.VariableModel(this.workspace, 'name', 'type', 'id');
       const origEvent = new Blockly.Events.VarCreate(varModel);
diff --git a/tests/mocha/event_var_delete_test.js b/tests/mocha/event_var_delete_test.js
index f086873d3..ef532c2d2 100644
--- a/tests/mocha/event_var_delete_test.js
+++ b/tests/mocha/event_var_delete_test.js
@@ -20,7 +20,18 @@ suite('Var Delete Event', function() {
   });
 
   suite('Serialization', function() {
-    test('events round-trip through JSON', function() {
+    test('untyped variable events round-trip through JSON', function() {
+      const varModel =
+          new Blockly.VariableModel(this.workspace, 'name', '', 'id');
+      const origEvent = new Blockly.Events.VarDelete(varModel);
+
+      const json = origEvent.toJson();
+      const newEvent = new Blockly.Events.fromJson(json, this.workspace);
+
+      chai.assert.deepEqual(newEvent, origEvent);
+    });
+
+    test('typed variable events round-trip through JSON', function() {
       const varModel =
           new Blockly.VariableModel(this.workspace, 'name', 'type', 'id');
       const origEvent = new Blockly.Events.VarDelete(varModel);