diff --git a/src/flextype/Foundation/Entries/Fields/CreatedAtField.php b/src/flextype/Foundation/Entries/Fields/CreatedAtField.php
index 92ea606c..0476b90e 100644
--- a/src/flextype/Foundation/Entries/Fields/CreatedAtField.php
+++ b/src/flextype/Foundation/Entries/Fields/CreatedAtField.php
@@ -14,7 +14,7 @@ if (flextype('registry')->get('flextype.settings.entries.fields.created_at.enabl
         if (flextype('entries')->getStorage('fetch_single.data.created_at') == null) {
             flextype('entries')->setStorage('fetch_single.data.created_at', (int) flextype('filesystem')->file(flextype('entries')->getFileLocation(flextype('entries')->getStorage('fetch_single.id')))->lastModified());
         } else {
-            flextype('entries')->setStorage('fetch_single.data.created_at', (int) strtotime(flextype('entries')->getStorage('fetch_single.data.created_at')));
+            flextype('entries')->setStorage('fetch_single.data.created_at', (int) strtotime((string) flextype('entries')->getStorage('fetch_single.data.created_at')));
         }
     });