diff --git a/INSTALL_MacOS.md b/INSTALL_MacOS.md
index a192af9c..0f0ded8d 100644
--- a/INSTALL_MacOS.md
+++ b/INSTALL_MacOS.md
@@ -3,11 +3,10 @@
 Get [Homebrew](https://brew.sh).
 
 ```sh
-# TCL9 should be supported soon (Q2 2025)
-brew install cairo tcl-tk@8 python3
+brew install cairo tcl-tk@8 python3 gnu-sed
 brew install --cask xquartz
 ./scripts/configure_mac
-# If you have both TCL8 and TCL9 installed you may need to verify TCL8 was selected.
+# If you have both TCL8 and TCL9 installed you may need to verify which was selected.
 make database/database.h
 make -j$(sysctl -n hw.ncpu)
 make install # may need sudo depending on your setup