diff --git a/README.md b/README.md
index 735edef0fc..b54956f773 100644
--- a/README.md
+++ b/README.md
@@ -64,6 +64,12 @@ brew install protobuf openssl flex bison icu4c pkg-config
 echo 'export PATH="$(brew --prefix openssl)/bin:$PATH"' >> ~/.zshrc
 ```
 
+If you get errors about missing `m4` you may have to install it manually:
+```
+brew install m4
+brew link --force m4
+```
+
 2. [Install Rust](https://www.rust-lang.org/tools/install)
 ```
 # recommended approach from https://www.rust-lang.org/tools/install