diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 9d4c8d5a1f53..dd4b80a9f1a9 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -116,7 +116,7 @@ static unsigned long get_timestamp(int this_cpu)
 	return cpu_clock(this_cpu) >> 30LL;  /* 2^30 ~= 10^9 */
 }
 
-static unsigned long get_sample_period(void)
+static u64 get_sample_period(void)
 {
 	/*
 	 * convert watchdog_thresh from seconds to ns
@@ -125,7 +125,7 @@ static unsigned long get_sample_period(void)
 	 * and hard thresholds) to increment before the
 	 * hardlockup detector generates a warning
 	 */
-	return get_softlockup_thresh() * (NSEC_PER_SEC / 5);
+	return get_softlockup_thresh() * ((u64)NSEC_PER_SEC / 5);
 }
 
 /* Commands for resetting the watchdog */