diff --git a/htdocs/core/class/stats.class.php b/htdocs/core/class/stats.class.php
index ae9a8e56e58..8128dd07ed8 100644
--- a/htdocs/core/class/stats.class.php
+++ b/htdocs/core/class/stats.class.php
@@ -86,7 +86,7 @@ abstract class Stats
 				$year = $year - 1;
 			}
 			while ($year <= $endyear) {
-				$datay[$year] = $this->getNbByMonth($year, $format);
+				$datay[$year] = $this->_getNbByMonth($year, $format);
 				$year++;
 			}