diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 1169d46126aca76674a89bad384f183c8f1b2b5e..6c0e9e2e1b82004ba8a9ba70586b76fbb1982899 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -52,7 +52,7 @@ static struct clocksource clocksource_itc = {
         .name           = "itc",
         .rating         = 350,
         .read           = itc_get_cycles,
-        .mask           = 0xffffffffffffffff,
+        .mask           = CLOCKSOURCE_MASK(64),
         .mult           = 0, /*to be caluclated*/
         .shift          = 16,
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 9a2694e5f8b98311ff435f3ce4733333c5682266..77bf4aa217a8afcb7e8eb505ed2b0f5d9a0542c0 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -73,7 +73,7 @@ static struct clocksource clocksource_hpet = {
         .name           = "hpet",
         .rating         = 250,
         .read           = read_hpet,
-        .mask           = 0xffffffffffffffff,
+        .mask           = CLOCKSOURCE_MASK(64),
         .mult           = 0, /*to be caluclated*/
         .shift          = 10,
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,