diff --git a/mediamtx.yml b/mediamtx.yml
index bb837278..b7339df5 100644
--- a/mediamtx.yml
+++ b/mediamtx.yml
@@ -547,7 +547,7 @@ pathDefaults:
   rpiCameraGain: 0
   # EV compensation of the image [-10, 10]
   rpiCameraEV: 0
-  # Region of interest, in format x,y,width,height
+  # Region of interest, in format x,y,width,height (all normalized between 0 and 1)
   rpiCameraROI:
   # Whether to enable HDR on Raspberry Camera 3.
   rpiCameraHDR: false