diff --git a/README.md b/README.md
index 213a6205dd..982f93f45f 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@ How to Build
 ------------
 
 grpc-java requires Netty 5, which is still in flux. The version we need can be
-found in the lib/netty submodule:
+found in the lib/netty submodule, which requires Maven 3.2 or higher to build:
 ```
 $ git submodule update --init
 $ cd lib/netty