diff --git a/payloads/libpayload/drivers/timer/arm64_arch_timer.c b/payloads/libpayload/drivers/timer/arm64_arch_timer.c
index 087d9e7..b4d2b86 100644
--- a/payloads/libpayload/drivers/timer/arm64_arch_timer.c
+++ b/payloads/libpayload/drivers/timer/arm64_arch_timer.c
@@ -32,7 +32,7 @@
 #include <arch/lib_helpers.h>
 #include <libpayload.h>
 
-uint64_t timer_hz(void)
+uint32_t timer_hz(void)
 {
 	return raw_read_cntfrq_el0();
 }
diff --git a/payloads/libpayload/drivers/timer/generic.c b/payloads/libpayload/drivers/timer/generic.c
index ef9eda5..bd5674b 100644
--- a/payloads/libpayload/drivers/timer/generic.c
+++ b/payloads/libpayload/drivers/timer/generic.c
@@ -33,7 +33,7 @@
 #include <assert.h>
 #include <libpayload.h>
 
-uint64_t timer_hz(void)
+uint32_t timer_hz(void)
 {
 	/* libc/time.c currently requires all timers to be at least 1MHz. */
 	assert(CONFIG_LP_TIMER_GENERIC_HZ >= 1000000);
diff --git a/payloads/libpayload/drivers/timer/rdtsc.c b/payloads/libpayload/drivers/timer/rdtsc.c
index cfd56b0..952bc0b 100644
--- a/payloads/libpayload/drivers/timer/rdtsc.c
+++ b/payloads/libpayload/drivers/timer/rdtsc.c
@@ -33,10 +33,12 @@
 
 #include <libpayload.h>
 #include <arch/rdtsc.h>
+#include <assert.h>
 
-uint64_t timer_hz(void)
+uint32_t timer_hz(void)
 {
-	return (uint64_t)lib_sysinfo.cpu_khz * 1000;
+	assert(UINT32_MAX / 1000 >= lib_sysinfo.cpu_khz);
+	return lib_sysinfo.cpu_khz * 1000;
 }
 
 uint64_t timer_raw_value(void)
diff --git a/payloads/libpayload/include/libpayload.h b/payloads/libpayload/include/libpayload.h
index e3c60ac..06c6de4 100644
--- a/payloads/libpayload/include/libpayload.h
+++ b/payloads/libpayload/include/libpayload.h
@@ -519,7 +519,7 @@
 
 /* Timer functions. */
 /* Defined by each architecture. */
-uint64_t timer_hz(void);
+uint32_t timer_hz(void);
 uint64_t timer_raw_value(void);
 uint64_t timer_us(uint64_t base);
 /* Generic. */
diff --git a/payloads/libpayload/libc/time.c b/payloads/libpayload/libc/time.c
index 6780008..c38dbfd 100644
--- a/payloads/libpayload/libc/time.c
+++ b/payloads/libpayload/libc/time.c
@@ -38,6 +38,7 @@
 #if CONFIG(LP_ARCH_X86) && CONFIG(LP_NVRAM)
 #include <arch/rdtsc.h>
 #endif
+#include <commonlib/bsd/gcd.h>
 #include <inttypes.h>
 
 extern u32 cpu_khz;
@@ -170,17 +171,21 @@
 
 u64 timer_us(u64 base)
 {
-	static u64 hz;
+	static u32 hz, mult = USECS_PER_SEC;
+	u32 div;
 
 	// Only check timer_hz once. Assume it doesn't change.
 	if (hz == 0) {
 		hz = timer_hz();
-		if (hz < 1000000) {
-			printf("Timer frequency %" PRIu64 " is too low, "
+		if (hz < mult) {
+			printf("Timer frequency %" PRIu32 " is too low, "
 			       "must be at least 1MHz.\n", hz);
 			halt();
 		}
+		div = gcd32(hz, mult);
+		hz /= div;
+		mult /= div;
 	}
 
-	return (1000000 * timer_raw_value()) / hz - base;
+	return (mult * timer_raw_value()) / hz - base;
 }