diff --git a/lib/naughty.lua.in b/lib/naughty.lua.in
index ce3270cd..7f53e44e 100644
--- a/lib/naughty.lua.in
+++ b/lib/naughty.lua.in
@@ -74,6 +74,7 @@ local counter = 1
 -- @field height Popup height
 -- @field width Popup width
 -- @field die Function to be executed on timeout
+-- @field id Unique notification id based on a counter
 -- @name notifications[position]
 -- @class table