diff --git a/CoinsPlugin.php b/CoinsPlugin.php
index 8138a4d..27f1d4f 100644
--- a/CoinsPlugin.php
+++ b/CoinsPlugin.php
@@ -112,7 +112,7 @@ function insertFooter(string $hookName, array $params) : bool
             $vars[] = ['rft.au', $author->getFullName()];
         }
 
-        if ($doi = $article->getStoredPubId('doi')) {
+        if ($doi = $publication->getStoredPubId('doi')) {
             $vars[] = ['rft_id', 'info:doi/' . $doi];
         }
         if ($publication->getData('pages')) {