diff --git a/cpu/native/periph/timer.c b/cpu/native/periph/timer.c
index ae3184dc08..7a80baa2e3 100644
--- a/cpu/native/periph/timer.c
+++ b/cpu/native/periph/timer.c
@@ -16,6 +16,8 @@
  * @brief       Native CPU periph/timer.h implementation
  *
  * Uses POSIX realtime clock and POSIX itimer to mimic hardware.
+ * This is done with the timer_settime(3), timer_create(3)  interfaces, which are
+ * sometimes found only in the -lrt library, and not in glibc.
  *
  * This is based on native's hwtimer implementation by Ludwig Knüpfer.
  * I removed the multiplexing, as ztimer does the same. (kaspar)