diff --git a/porting/npl/riot/include/nimble/nimble_npl_os.h b/porting/npl/riot/include/nimble/nimble_npl_os.h
index 61c1ea8a0..7216635dd 100644
--- a/porting/npl/riot/include/nimble/nimble_npl_os.h
+++ b/porting/npl/riot/include/nimble/nimble_npl_os.h
@@ -100,7 +100,8 @@ ble_npl_eventq_get(struct ble_npl_eventq *evq, ble_npl_time_t tmo)
     } else if (tmo == BLE_NPL_TIME_FOREVER) {
         return (struct ble_npl_event *)event_wait(&evq->q);
     } else {
-        return (struct ble_npl_event *)event_wait_timeout(&evq->q, (tmo * 1000));
+        return (struct ble_npl_event *)event_wait_timeout(&evq->q,
+                                                          (tmo * US_PER_MS));
     }
 }
 
@@ -227,7 +228,7 @@ ble_npl_callout_set_arg(struct ble_npl_callout *co, void *arg)
 static inline uint32_t
 ble_npl_time_get(void)
 {
-    return xtimer_now_usec() / 1000;
+    return xtimer_now_usec64() / US_PER_MS;
 }
 
 static inline ble_npl_error_t
@@ -259,7 +260,7 @@ ble_npl_time_ticks_to_ms32(ble_npl_time_t ticks)
 static inline void
 ble_npl_time_delay(ble_npl_time_t ticks)
 {
-    xtimer_usleep(ticks * 1000);
+    xtimer_usleep(ticks * US_PER_MS);
 }
 
 static inline uint32_t
diff --git a/porting/npl/riot/src/npl_os_riot.c b/porting/npl/riot/src/npl_os_riot.c
index cc3909e7d..aa03aa397 100644
--- a/porting/npl/riot/src/npl_os_riot.c
+++ b/porting/npl/riot/src/npl_os_riot.c
@@ -39,9 +39,9 @@ ble_npl_sem_pend(struct ble_npl_sem *sem, ble_npl_time_t timeout)
     struct timespec abs;
     uint64_t time;
 
-    time = xtimer_now_usec64() + ble_npl_time_ticks_to_ms32(timeout) * 1000;
-    abs.tv_sec = (time_t)(time / 1000000);
-    abs.tv_nsec = (long)((time % 1000000) * 1000);
+    time = xtimer_now_usec64() + ble_npl_time_ticks_to_ms32(timeout) * US_PER_MS;
+    abs.tv_sec = (time_t)(time / US_PER_SEC);
+    abs.tv_nsec = (long)((time % US_PER_SEC) * NS_PER_US);
 
     rc = sem_timedwait(&sem->sem, &abs);
 
@@ -62,8 +62,8 @@ ble_npl_error_t
 ble_npl_callout_reset(struct ble_npl_callout *c, ble_npl_time_t ticks)
 {
     uint32_t now = xtimer_now_usec();
-    c->target_ticks = (ble_npl_time_t)((now / 1000) + ticks);
-    xtimer_set(&c->timer, ((ticks * 1000) - ((xtimer_now_usec() - now) / 1000)));
+    c->target_ticks = (ble_npl_time_t)((now / US_PER_MS) + ticks);
+    xtimer_set(&c->timer, ((ticks * US_PER_MS) - ((xtimer_now_usec() - now) / US_PER_MS)));
     return BLE_NPL_OK;
 }
 
@@ -72,5 +72,5 @@ ble_npl_callout_remaining_ticks(struct ble_npl_callout *co,
                                 ble_npl_time_t time)
 {
     uint32_t now = xtimer_now_usec();
-    return ((uint32_t)co->target_ticks) - (now / 1000);
+    return ((uint32_t)co->target_ticks) - (now / US_PER_MS);
 }