diff --git a/drivers/rtc/rtc-mrst.c b/drivers/rtc/rtc-mrst.c
index b2f0968..0cec565 100644
--- a/drivers/rtc/rtc-mrst.c
+++ b/drivers/rtc/rtc-mrst.c
@@ -380,7 +380,7 @@
 cleanup0:
 	dev_set_drvdata(dev, NULL);
 	mrst_rtc.dev = NULL;
-	release_region(iomem->start, iomem->end + 1 - iomem->start);
+	release_mem_region(iomem->start, resource_size(iomem));
 	dev_err(dev, "rtc-mrst: unable to initialise\n");
 	return retval;
 }
@@ -406,7 +406,7 @@
 	mrst->rtc = NULL;
 
 	iomem = mrst->iomem;
-	release_region(iomem->start, iomem->end + 1 - iomem->start);
+	release_mem_region(iomem->start, resource_size(iomem));
 	mrst->iomem = NULL;
 
 	mrst->dev = NULL;