diff --git a/core/blockly.js b/core/blockly.js
index 6962bc2b2..910fb1658 100644
--- a/core/blockly.js
+++ b/core/blockly.js
@@ -693,7 +693,12 @@ Blockly.setStyle = function(style) {
   workspace.refreshToolboxSelection();
   for (var i = 0; i < blocks.length; i++) {
     var block = blocks[i];
-    block.setStyle(block.getStyleName());
+    var blockStyleName = block.getStyleName();
+
+    block.setStyle(blockStyleName);
+    if (block.mutator) {
+      block.mutator.updateBlockStyle(blockStyleName);
+    }
   }
 
   var event = new Blockly.Events.Ui(null, 'styleChanged');
diff --git a/core/mutator.js b/core/mutator.js
index b1367749c..ed85ce149 100644
--- a/core/mutator.js
+++ b/core/mutator.js
@@ -397,6 +397,25 @@ Blockly.Mutator.prototype.dispose = function() {
   Blockly.Icon.prototype.dispose.call(this);
 };
 
+/**
+ * Update the styles on all blocks in the mutator.
+ * @public
+ */
+Blockly.Mutator.prototype.updateBlockStyle = function() {
+  if (this.workspace_ && this.workspace_.getAllBlocks()){
+    var workspaceBlocks = this.workspace_.getAllBlocks();
+    for (var i = 0; i < workspaceBlocks.length; i++) {
+      var block = workspaceBlocks[i];
+      block.setStyle(block.getStyleName());
+    }
+    var flyoutBlocks = this.workspace_.flyout_.workspace_.getAllBlocks();
+    for (var i = 0; i < flyoutBlocks.length; i++) {
+      var block = flyoutBlocks[i];
+      block.setStyle(block.getStyleName());
+    }
+  }
+};
+
 /**
  * Reconnect an block to a mutated input.
  * @param {Blockly.Connection} connectionChild Connection on child block.