diff --git a/common/legacy.php b/common/legacy.php
index d1499de9d..4a1e8177e 100644
--- a/common/legacy.php
+++ b/common/legacy.php
@@ -244,6 +244,10 @@ function setUserSequence($seq): void
 	}
 	$seq = intval($seq);
 	$_SESSION['seq'][$seq] = $seq;
+	if (count($_SESSION['seq']) > 1000)
+	{
+		$_SESSION['seq'] = array_slice($_SESSION['seq'], 600, null, true);
+	}
 }
 
 /**