diff --git a/single.php b/single.php
index c2b391b..a8dca48 100644
--- a/single.php
+++ b/single.php
@@ -95,6 +95,7 @@
 							));
 							foreach($tagebuch as $tb){
 								if(get_field('urlaub',$tb->ID)->ID === get_the_ID()){
+									$thumb = wp_get_attachment_image_src( get_post_thumbnail_id($tb->ID), 'post-thumb' );
 									echo('<a href="'.get_the_permalink($tb->ID).'" id="post-'.$tb->ID.'" ');
 									post_class('post');
 									echo(' style="background-image: url('.$thumb['0'].');"><div class="post-overlay">');