diff --git a/@overflow/sensor/component/sensor-list.component.ts b/@overflow/sensor/component/sensor-list.component.ts
index 8b48d98..e8c0724 100644
--- a/@overflow/sensor/component/sensor-list.component.ts
+++ b/@overflow/sensor/component/sensor-list.component.ts
@@ -37,7 +37,7 @@ export class SensorListComponent implements OnInit, OnChanges {
   }
 
   ngOnInit() {
-    if (1 > this.pageNo) {
+    if (undefined === this.pageNo || 1 > this.pageNo) {
       this.pageNo = 0;
     }