diff --git a/src/lib/custom-style.html b/src/lib/custom-style.html
index 183197ba0f..688237d439 100644
--- a/src/lib/custom-style.html
+++ b/src/lib/custom-style.html
@@ -129,6 +129,10 @@
         this.__appliedElement.__cssBuild = this.__cssBuild;
       }
       // needed becuase elements in imports do not get 'attached'
+      // TODO(sorvell): we could only do this iff this.ownerDocument != document;
+      // however, if we do that, we also have to change the `attached`
+      // code to go at `_beforeAttached` time because this is when 
+      // elements produce styles (otherwise this breaks @apply shim)
       this._tryApply();
     },