diff --git a/lib/utils.js b/lib/utils.js
index d83e68d..a75d261 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -76,7 +76,7 @@ export function toFilePath(slug) {
 
 export function toSlug(filePath) {
 
-    if (Node.isFile(filePath)) {
+    if (Node.isFile(filePath) && filePath.includes(postsDirectory)) {
         return filePath.replace(postsDirectory, '')
             .replaceAll('/','__')
             .replaceAll(' ','--')