diff --git a/INSTALL.md b/INSTALL.md
index 6cfa1b6cbaf34ad1c9b6557cf2b75e159ebd611d..343f6fb8ca2ca84e9db268cf5e42f20be7a04d04 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -46,6 +46,15 @@ packages, which you can get from [Homebrew](https://brew.sh):
  $ brew install autoconf automake libtool shtool
 ```
 
+Tip: when building, 
+you *may* want to explicitly set the `LIBTOOL` and `LIBTOOLIZE`
+environment variables when running `make` to ensure the version
+installed by `brew` is being used:
+
+```sh
+ $ LIBTOOL=glibtool LIBTOOLIZE=glibtoolize make
+```
+
 If you plan to build from source and run tests, install the following as well:
 ```sh
  $ brew install gflags