diff --git a/index.js b/index.js
index 60be5c3..86223a8 100644
--- a/index.js
+++ b/index.js
@@ -33,8 +33,8 @@ module.exports = new Transformer({
       }
     )
     const shouldInvalidateOnStartup = riotConfig &&
-      riotConfig.filePath.endsWith('.js') ||
-      riotConfig.filePath.endsWith(CONFIG_FILES[0])
+      riotConfig?.filePath?.endsWith('.js') ||
+      riotConfig?.filePath?.endsWith(CONFIG_FILES[0])
 
     if (shouldInvalidateOnStartup) {
       config.invalidateOnStartup()