diff --git a/src/virtual-machine.js b/src/virtual-machine.js
index 43ada32cb..e428b7727 100644
--- a/src/virtual-machine.js
+++ b/src/virtual-machine.js
@@ -896,7 +896,8 @@ class VirtualMachine extends EventEmitter {
     }
 
     /**
-     * Set the bitmap adapter for the VM/runtime, which converts scratch 2 svgs to scratch 3 bitmaps
+     * Set the bitmap adapter for the VM/runtime, which converts scratch 2
+     * bitmaps to scratch 3 bitmaps. (Scratch 3 bitmaps are all bitmap resolution 2)
      * @param {!function} bitmapAdapter The adapter to attach
      */
     attachV2BitmapAdapter (bitmapAdapter) {