diff --git a/tag/lib.php b/tag/lib.php
index c9702da..6e6ad97 100644
--- a/tag/lib.php
+++ b/tag/lib.php
@@ -854,7 +854,7 @@ function tag_compute_correlations($min_correlation=2) {
         //var_dump($correlated);
 
         //saves correlation info in the caching table
-        if ($tag_correlation_obj = $DB->get_record('tag_correlation', array('tagid'=>$tag->id), 'tagid')) {
+        if ($tag_correlation_obj = $DB->get_record('tag_correlation', array('tagid'=>$tag->id), 'id', 'tagid')) {
             $tag_correlation_obj->correlatedtags = $correlated;
             $DB->update_record('tag_correlation', $tag_correlation_obj);
         } else {