diff --git a/core/events/block/base.js b/core/events/block/base.js
index 6c9063151..26dc0ee72 100644
--- a/core/events/block/base.js
+++ b/core/events/block/base.js
@@ -53,9 +53,7 @@ goog.inherits(Blockly.Events.BlockBase, Blockly.Events.Abstract);
  */
 Blockly.Events.BlockBase.prototype.toJson = function() {
   var json = Blockly.Events.BlockBase.superClass_.toJson.call(this);
-  if (this.blockId) {
-    json['blockId'] = this.blockId;
-  }
+  json['blockId'] = this.blockId;
   return json;
 };
 
diff --git a/core/events/variable/base.js b/core/events/variable/base.js
index 395df2e72..c542585a1 100644
--- a/core/events/variable/base.js
+++ b/core/events/variable/base.js
@@ -54,9 +54,7 @@ goog.inherits(Blockly.Events.VarBase, Blockly.Events.Abstract);
  */
 Blockly.Events.VarBase.prototype.toJson = function() {
   var json = Blockly.Events.VarBase.superClass_.toJson.call(this);
-  if (this.varId) {
-    json['varId'] = this.varId;
-  }
+  json['varId'] = this.varId;
   return json;
 };