diff --git a/libraries/build_html_for_db.lib.php b/libraries/build_html_for_db.lib.php
index b0d0176685..694e916b55 100644
--- a/libraries/build_html_for_db.lib.php
+++ b/libraries/build_html_for_db.lib.php
@@ -103,6 +103,7 @@ function PMA_buildHtmlForDb(
 
     foreach ($column_order as $stat_name => $stat) {
         if (array_key_exists($stat_name, $current)) {
+            $unit = '';
             if (is_numeric($stat['footer'])) {
                 $column_order[$stat_name]['footer'] += $current[$stat_name];
             }