diff --git a/core/field_variable.js b/core/field_variable.js
index 850e2c378..336c84a02 100644
--- a/core/field_variable.js
+++ b/core/field_variable.js
@@ -147,11 +147,8 @@ Blockly.FieldVariable.prototype.initModel = function() {
       this.sourceBlock_.workspace, null,
       this.defaultVariableName, this.defaultType_);
 
-  // Don't fire a change event for this setValue.  It would have null as the
-  // old value, which is not valid.
-  Blockly.Events.disable();
-  this.setValue(variable.getId());
-  Blockly.Events.enable();
+  // Don't call setValue because we don't want to cause a rerender.
+  this.doValueUpdate_(variable.getId());
 };
 
 /**
diff --git a/core/mutator.js b/core/mutator.js
index decb81f3a..c864c9f8d 100644
--- a/core/mutator.js
+++ b/core/mutator.js
@@ -372,15 +372,10 @@ Blockly.Mutator.prototype.workspaceChanged_ = function(e) {
     var block = this.block_;
     var oldMutationDom = block.mutationToDom();
     var oldMutation = oldMutationDom && Blockly.Xml.domToText(oldMutationDom);
-    // Switch off rendering while the source block is rebuilt.
-    var savedRendered = block.rendered;
-    block.rendered = false;
     // Allow the source block to rebuild itself.
     block.compose(this.rootBlock_);
-    // Restore rendering and show the changes.
-    block.rendered = savedRendered;
-    // Mutation may have added some elements that need initializing.
     block.initSvg();
+    block.render();
     var newMutationDom = block.mutationToDom();
     var newMutation = newMutationDom && Blockly.Xml.domToText(newMutationDom);
     if (oldMutation != newMutation) {
@@ -394,9 +389,6 @@ Blockly.Mutator.prototype.workspaceChanged_ = function(e) {
         Blockly.Events.setGroup(false);
       }, Blockly.BUMP_DELAY);
     }
-    if (block.rendered) {
-      block.render();
-    }
 
     if (oldMutation != newMutation &&
         this.workspace_.keyboardAccessibilityMode) {