diff --git a/functions.php b/functions.php
index e1fc66b0d..fee40cb9d 100644
--- a/functions.php
+++ b/functions.php
@@ -347,7 +347,7 @@
 				}
 			}
 
-			db_query($link, "UPDATE ttrss_feeds SET last_updated = NOW() WHERE id = $feed");
+			db_query($link, "UPDATE ttrss_feeds SET last_updated = NOW() WHERE id = '$feed'");
 
 		}