diff --git a/lib/subfont.js b/lib/subfont.js
index 0357d90c..19630d02 100644
--- a/lib/subfont.js
+++ b/lib/subfont.js
@@ -109,6 +109,7 @@ module.exports = async ({
   for (const asset of assetGraph.findAssets({
     isDirty: true,
     isInline: false,
+    isLoaded: true,
     type: 'Css'
   })) {
     if (!asset.url.startsWith(assetGraph.root)) {