diff --git a/DDDigi/README.md b/DDDigi/README.md
index 5a60251b52b68595bfb15d103832c19ca9133db5..5e56337032d88ec2b8cc66873fa5742e61956878 100644
--- a/DDDigi/README.md
+++ b/DDDigi/README.md
@@ -156,5 +156,11 @@ DigiAttenuatorSequence
     |`.t0`            | double          | Time constant for exponential signal decay.                     |
 
 
+DigiDepositSmearPositionTrack
+-----------------------------
+
+- Smear energy deposit positions by an ellipse of the track passing in the
+  x-y plane.
+
 
 ![HORIZON2020](../doc/usermanuals/DD4hep/figures/AIDAinnova.png)