diff --git a/util/doxygen b/util/doxygen
index 56422c869..4db42159e 100755
--- a/util/doxygen
+++ b/util/doxygen
@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 # generates doxygen source code documentatiin
+# Too use, sudo apt install doxygen
+# or your package manager equivalent
 
     doxygen util/Doxyfile
     echo open the following link in your browser