diff --git a/src/lib/formatCSS.js b/src/lib/formatCSS.js
index 6ff7fc40ba10..75adde499427 100644
--- a/src/lib/formatCSS.js
+++ b/src/lib/formatCSS.js
@@ -11,5 +11,7 @@ function indentRecursive(node, indent = 0) {
 
 export default function formatNodes(root) {
   indentRecursive(root)
-  root.first.raws.before = ''
+  if (root.first) {
+    root.first.raws.before = ''
+  }
 }