diff --git a/docs/source/yosys_internals/formats/cell_library.rst b/docs/source/yosys_internals/formats/cell_library.rst
index 7a19255a3d0..2e30ee25c5d 100644
--- a/docs/source/yosys_internals/formats/cell_library.rst
+++ b/docs/source/yosys_internals/formats/cell_library.rst
@@ -1237,3 +1237,5 @@ file via ABC using the abc pass.
 .. todo:: Add information about ``$slice`` and ``$concat`` cells.
 
 .. todo:: Add information about ``$alu``, ``$fa``, and ``$lcu`` cells.
+
+.. todo:: Add information about ``$demux`` cell.
\ No newline at end of file