diff --git a/arch/arm/src/armv7-r/arm_timer.c b/arch/arm/src/armv7-r/arm_timer.c
index dfb3e541c03..08f9d24a6c4 100644
--- a/arch/arm/src/armv7-r/arm_timer.c
+++ b/arch/arm/src/armv7-r/arm_timer.c
@@ -143,7 +143,9 @@ static inline void arm_timer_set_cval(uint64_t cval)
 
 static inline uint64_t nsec_from_count(uint64_t count, uint32_t freq)
 {
-  return (uint64_t)count * NSEC_PER_SEC / freq;
+  uint64_t sec = count / freq;
+  uint64_t nsec = (count % freq) * NSEC_PER_SEC / freq;
+  return sec * NSEC_PER_SEC + nsec;
 }
 
 static inline uint64_t nsec_to_count(uint32_t nsec, uint32_t freq)