diff --git a/src/INSTALL b/src/INSTALL
index 96f32607fc..054df8ac24 100644
--- a/src/INSTALL
+++ b/src/INSTALL
@@ -70,7 +70,9 @@ To build Vim on Ubuntu from scratch on a clean system using git:
 	% make reconfig
 
 	Add GUI (GTK4) support:
-	% sudo apt install libgtk-3-dev
+	% sudo apt install libgtk-4-dev
+	(GTK4 is not the default; configure with
+	 --enable-gui=gtk4 to select it.)
 	% make reconfig
 
 	Add Python 3 support: