Update protobuf version
diff --git a/examples/cpp/helloworld/Makefile b/examples/cpp/helloworld/Makefile
index f2093af..d7c4b77 100644
--- a/examples/cpp/helloworld/Makefile
+++ b/examples/cpp/helloworld/Makefile
@@ -92,7 +92,7 @@
 	@echo "Please install Google protocol buffers 3.0.0 and its compiler."
 	@echo "You can find it here:"
 	@echo
-	@echo "   https://github.com/google/protobuf/releases/tag/v3.0.0-alpha-1"
+	@echo "   https://github.com/google/protobuf/releases/tag/v3.0.0-beta-2"
 	@echo
 	@echo "Here is what I get when trying to evaluate your version of protoc:"
 	@echo