diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
index 7bc0fb1df1e0..001b2c931125 100644
--- a/drivers/watchdog/aspeed_wdt.c
+++ b/drivers/watchdog/aspeed_wdt.c
@@ -252,7 +252,7 @@ static void aspeed_wdt_update_bootstatus(struct platform_device *pdev,
 
 	if (!of_device_is_compatible(pdev->dev.of_node, "aspeed,ast2400-wdt")) {
 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-		idx = ((intptr_t)wdt->base & 0x00000fff) / resource_size(res);
+		idx = ((intptr_t)wdt->base & 0x00000fff) / (uintptr_t)resource_size(res);
 	}
 
 	scu_base = syscon_regmap_lookup_by_compatible(scu.compatible);