diff --git a/src/libcamera/control_ids_core.yaml b/src/libcamera/control_ids_core.yaml
index 566e1533..eec4b4f9 100644
--- a/src/libcamera/control_ids_core.yaml
+++ b/src/libcamera/control_ids_core.yaml
@@ -1274,7 +1274,8 @@ 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. Like SensorTimestamp, the timestamp value is
+        expressed in nanoseconds.
 
         Being a wall clock measurement, it can be used to synchronise timing
         across different devices.
diff --git a/src/libcamera/pipeline/rpi/pisp/pisp.cpp b/src/libcamera/pipeline/rpi/pisp/pisp.cpp
index 2df91bac..92b9070c 100644
--- a/src/libcamera/pipeline/rpi/pisp/pisp.cpp
+++ b/src/libcamera/pipeline/rpi/pisp/pisp.cpp
@@ -1760,7 +1760,7 @@ void PiSPCameraData::cfeBufferDequeue(FrameBuffer *buffer)
 		 */
 		wallClockRecovery_.addSample();
 		uint64_t sensorTimestamp = buffer->metadata().timestamp;
-		uint64_t wallClockTimestamp = wallClockRecovery_.getOutput(sensorTimestamp / 1000);
+		uint64_t wallClockTimestamp = wallClockRecovery_.getOutput(sensorTimestamp);
 
 		ctrl.set(controls::SensorTimestamp, sensorTimestamp);
 		ctrl.set(controls::FrameWallClock, wallClockTimestamp);
diff --git a/src/libcamera/pipeline/rpi/vc4/vc4.cpp b/src/libcamera/pipeline/rpi/vc4/vc4.cpp
index e99a7edf..5cadef52 100644
--- a/src/libcamera/pipeline/rpi/vc4/vc4.cpp
+++ b/src/libcamera/pipeline/rpi/vc4/vc4.cpp
@@ -778,7 +778,7 @@ void Vc4CameraData::unicamBufferDequeue(FrameBuffer *buffer)
 		 */
 		wallClockRecovery_.addSample();
 		uint64_t sensorTimestamp = buffer->metadata().timestamp;
-		uint64_t wallClockTimestamp = wallClockRecovery_.getOutput(sensorTimestamp / 1000);
+		uint64_t wallClockTimestamp = wallClockRecovery_.getOutput(sensorTimestamp);
 
 		ctrl.set(controls::SensorTimestamp, sensorTimestamp);
 		ctrl.set(controls::FrameWallClock, wallClockTimestamp);