diff --git a/README.md b/README.md
index fdd141e32..affd58689 100644
--- a/README.md
+++ b/README.md
@@ -151,6 +151,9 @@ The most recent frame that frigate has finished processing. It is a full resolut
 Example parameters:
 - `h=300`: resizes the image to 300 pixes tall
 
+### `/<camera_name>/mask.jpg`
+The mask superimposed on the most recent frame that the frigate has finished processing.
+
 ### `/debug/stats`
 Contains some granular debug info that can be used for sensors in HomeAssistant. See details below.