diff --git a/packages/core/src/sheet.js b/packages/core/src/sheet.js
index 761237a8..305b61d2 100644
--- a/packages/core/src/sheet.js
+++ b/packages/core/src/sheet.js
@@ -1,4 +1,4 @@
-import { getNonce } from './utility/getNonce'
+import { getNonce } from './utility/getNonce.js'
 
 /** @typedef {import('./sheet').RuleGroup} RuleGroup */
 /** @typedef {import('./sheet').RuleGroupNames} RuleGroupNames */