diff --git a/protos/hellostreamingworld.proto b/protos/hellostreamingworld.proto
index ec8405c78b30f25abe8c30d668a714cb84dce945..bd5af3b2d5b4f4ed28ea53faa9cd9b8f55a62884 100644
--- a/protos/hellostreamingworld.proto
+++ b/protos/hellostreamingworld.proto
@@ -30,6 +30,7 @@
 syntax = "proto3";
 
 option java_package = "ex.grpc";
+option objc_class_prefix = "HSW";
 
 package hellostreamingworld;
 
diff --git a/protos/helloworld.proto b/protos/helloworld.proto
index 6281c934ae492cfa34c5ecaf5e154a96b52f8a21..7d58870a7084205feb2e9ef63dfc8b9789078fb1 100644
--- a/protos/helloworld.proto
+++ b/protos/helloworld.proto
@@ -30,6 +30,7 @@
 syntax = "proto3";
 
 option java_package = "io.grpc.examples";
+option objc_class_prefix = "HLW";
 
 package helloworld;
 
diff --git a/protos/route_guide.proto b/protos/route_guide.proto
index 37590490f44777dc768a3db33d6c6fb83e9016c9..bfde5f1ead67cdac9055fb2e51ebc5145a1996e5 100644
--- a/protos/route_guide.proto
+++ b/protos/route_guide.proto
@@ -30,6 +30,7 @@
 syntax = "proto3";
 
 option java_package = "ex.grpc";
+option objc_class_prefix = "RTG";
 
 package examples;