diff --git a/classes/rssutils.php b/classes/rssutils.php
index 8b3c7c0d0..aa051418b 100755
--- a/classes/rssutils.php
+++ b/classes/rssutils.php
@@ -830,7 +830,7 @@ class RSSUtils {
 								$start = microtime(true);
 								$article = $plugin->hook_article_filter_action($article, $pfaction);
 
-								Debug::log(sprintf("=== %.4f (sec)"), Debug::$LOG_VERBOSE);
+								Debug::log(sprintf("=== %.4f (sec)", Debug::$LOG_VERBOSE));
 							} else {
 								Debug::log("??? $pfclass: plugin object not found.", Debug::$LOG_VERBOSE);
 							}