diff --git a/README.md b/README.md
index c199afbc3dc2a115b6155283b2cb24b260753f4d..b4342dfa42f04524ef9f944311fa43e45a830573 100644
--- a/README.md
+++ b/README.md
@@ -39,11 +39,12 @@ Additional steps may be needed on other operating systems, for the required `GSL
 
 For **Debian or Ubuntu**, this should typically work:\
 `sudo apt-get install libgmp3-dev`\
-`sudo apt-get install libglpk-dev` \
 `sudo apt-get install libnlopt-dev`\
+`sudo apt-get install libglpk-dev` \
 
-**Mac** users should install [HomeBrew](https://brew.sh/) and then run 
-`brew install gsl` and `brew install glpk`.
+**Mac** users may find [HomeBrew](https://brew.sh/) useful: install it and then run 
+`brew install gsl` and `brew install glpk`. However, my limited experience with it was deceptive. It did not tell
+when no writeable `/usr/local/include` directory existed, preventing the installation of the `GSL`. The alternative installation procedure described [here](https://gist.github.com/TysonRayJones/af7bedcdb8dc59868c7966232b4da903#osx) has then been useful.
 
 Possibly obsolete: once upon a time on **Windows** I had to \cr
  `pacman -S mingw-w64-x86_64-nlopt`; and