diff --git a/src/ruby/README.md b/src/ruby/README.md
index 8187d7f3b5c..a98f6f034c7 100644
--- a/src/ruby/README.md
+++ b/src/ruby/README.md
@@ -18,6 +18,11 @@ INSTALLATION
 gem install grpc
 ```
 
+If using a Gemfile and you wish to pull from a git repository or GitHub, make sure to tell bundler to retrieve submodules:
+```
+gem 'grpc', github: 'grpc/grpc', submodules: true
+```
+
 BUILD FROM SOURCE
 ---------------------
 - Clone this repository