diff --git a/README.md b/README.md
index 743a8a0..a53a727 100644
--- a/README.md
+++ b/README.md
@@ -52,8 +52,9 @@ In order to transform from REST to gRPC completely, you need to use three of hoo
 ```lua
 ## 0. prepare proto file import_paths
 init_by_lua_block {
+  -- Define global import paths
   PROTOC_IMPORT_PATHS = {
-    "/usr/local/include"
+    "/usr/local/protoc/include"
   }
 }
 
@@ -102,6 +103,7 @@ server {
       ngx.header["Content-Type"] = "application/json"
     }
 
+    grpc_set_header TE trailers;
     grpc_set_header Content-Type application/grpc;
     grpc_pass localhost:9000;
   }
diff --git a/example/gateway/conf/server.conf b/example/gateway/conf/server.conf
index 12289eb..ac66923 100644
--- a/example/gateway/conf/server.conf
+++ b/example/gateway/conf/server.conf
@@ -1,5 +1,6 @@
 lua_code_cache off;
 
+## 0. prepare proto file import_paths
 init_by_lua_block {
   -- Define global import paths
   PROTOC_IMPORT_PATHS = {
@@ -25,36 +26,42 @@ server {
   }
 
   location /rest {
+
+## 1. Transform request from REST to gRPC
     access_by_lua_block {
       local proto = require("grpc-gateway.proto")
-      local gateway = require("grpc-gateway.request")
+      local grequest = require("grpc-gateway.request")
       local p, err = proto.new("/etc/proto/helloworld.proto")
       if err then
         ngx.log(ngx.ERR, ("proto load error: %s"):format(err))
         return
       end
-      local req = gateway.new(p)
+      local req = grequest.new(p)
       err = req:transform("helloworld.Greeter", "SayHello")
       if err then
-        ngx.log(ngx.ERR, ("trasnform request error: %s"):format(err))
+        ngx.log(ngx.ERR, ("transform request error: %s"):format(err))
         return
       end
     }
+
+## 2. Transform response from gPRC to JSON
     body_filter_by_lua_block {
       local proto = require("grpc-gateway.proto")
-      local gateway = require("grpc-gateway.response")
+      local gresponse = require("grpc-gateway.response")
       local p, err = proto.new("/etc/proto/helloworld.proto")
       if err then
         ngx.log(ngx.ERR, ("proto load error: %s"):format(err))
         return
       end
-      local resp = gateway.new(p)
+      local resp = gresponse.new(p)
       err = resp:transform("helloworld.Greeter", "SayHello")
       if err then
-        ngx.log(ngx.ERR, ("trasnform response error: %s"):format(err))
+        ngx.log(ngx.ERR, ("transform response error: %s"):format(err))
         return
       end
     }
+
+## 3. Swap response header to `Content-Type: application/json`
     header_filter_by_lua_block {
       ngx.header["Content-Type"] = "application/json"
     }