diff --git a/drivers/rtc/rtc-vr41xx.c b/drivers/rtc/rtc-vr41xx.c
index fadddac1e5a..c3244244e8c 100644
--- a/drivers/rtc/rtc-vr41xx.c
+++ b/drivers/rtc/rtc-vr41xx.c
@@ -327,7 +327,7 @@ static int __devinit rtc_probe(struct platform_device *pdev)
 	if (!res)
 		return -EBUSY;
 
-	rtc1_base = ioremap(res->start, res->end - res->start + 1);
+	rtc1_base = ioremap(res->start, resource_size(res));
 	if (!rtc1_base)
 		return -EBUSY;
 
@@ -337,7 +337,7 @@ static int __devinit rtc_probe(struct platform_device *pdev)
 		goto err_rtc1_iounmap;
 	}
 
-	rtc2_base = ioremap(res->start, res->end - res->start + 1);
+	rtc2_base = ioremap(res->start, resource_size(res));
 	if (!rtc2_base) {
 		retval = -EBUSY;
 		goto err_rtc1_iounmap;