diff --git a/web/templates/index.html b/web/templates/index.html
index a195345..7e00f25 100644
--- a/web/templates/index.html
+++ b/web/templates/index.html
@@ -1415,6 +1415,7 @@
     }
 
     function startStatsPolling() {
+        if (statsInterval) return;  // already polling; keep the history
         document.getElementById('sys-stats').style.display = 'block';
         statHistory.cpu = []; statHistory.mem = []; statHistory.disk = [];
         pollSystemStats();