diff --git a/packages/core/src/sheet.js b/packages/core/src/sheet.js
index 1603b4fe..0834b34b 100644
--- a/packages/core/src/sheet.js
+++ b/packages/core/src/sheet.js
@@ -21,8 +21,7 @@ const isSheetAccessible = (/** @type {CSSStyleSheet} */ sheet) => {
 	}
 
 	try {
-		sheet.cssRules
-		return true
+		return !!sheet.cssRules
 	} catch (e) {
 		return false
 	}