diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 412a1e04a922..5aef087d42d0 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -347,7 +347,7 @@ static void acpi_unmap(acpi_physical_address pg_off, void __iomem *vaddr)
 	unsigned long pfn;
 
 	pfn = pg_off >> PAGE_SHIFT;
-	if (page_is_ram(pfn))
+	if (should_use_kmap(pfn))
 		kunmap(pfn_to_page(pfn));
 	else
 		iounmap(vaddr);