diff --git a/src/libcamera/control_ids_core.yaml b/src/libcamera/control_ids_core.yaml
index 028919ef3..0708ec7cc 100644
--- a/src/libcamera/control_ids_core.yaml
+++ b/src/libcamera/control_ids_core.yaml
@@ -1272,7 +1272,8 @@ controls:
       description: |
         This timestamp corresponds to the same moment in time as the
         SensorTimestamp, but is represented as a wall clock time as measured by
-        the CLOCK_REALTIME clock.
+        the CLOCK_REALTIME clock. Note that this control measures time in units
+        of microseconds as opposed to nanoseconds in case of SensorTimestamp.

         Being a wall clock measurement, it can be used to synchronise timing
         across different devices.