diff --git a/tonic-build/src/lib.rs b/tonic-build/src/lib.rs
index 50def0a..f0d1b1e 100644
--- a/tonic-build/src/lib.rs
+++ b/tonic-build/src/lib.rs
@@ -69,7 +69,7 @@ use std::{
 };
 
 mod client;
-mod service;
+mod server;
 
 /// Service generator builder.
 #[derive(Debug, Clone)]
@@ -207,7 +207,7 @@ impl prost_build::ServiceGenerator for ServiceGenerator {
         let path = "super";
 
         if self.builder.build_server {
-            let server = service::generate(&service, path);
+            let server = server::generate(&service, path);
             self.servers.extend(server);
         }
 
diff --git a/tonic-build/src/service.rs b/tonic-build/src/server.rs
similarity index 96%
rename from tonic-build/src/service.rs
rename to tonic-build/src/server.rs
index d18a642..bc11cc2 100644
--- a/tonic-build/src/service.rs
+++ b/tonic-build/src/server.rs
@@ -124,14 +124,18 @@ fn generate_trait_methods(service: &Service, proto_path: &str) -> TokenStream {
                 quote! {
                     #method_doc
                     async fn #name(&self, request: tonic::Request<#req_message>)
-                        -> Result<tonic::Response<#res_message>, tonic::Status>;
+                        -> Result<tonic::Response<#res_message>, tonic::Status> {
+                            Err(tonic::Status::unimplemented("Not yet implemented"))
+                        }
                 }
             }
             (true, false) => {
                 quote! {
                     #method_doc
                     async fn #name(&self, request: tonic::Request<tonic::Streaming<#req_message>>)
-                        -> Result<tonic::Response<#res_message>, tonic::Status>;
+                        -> Result<tonic::Response<#res_message>, tonic::Status> {
+                            Err(tonic::Status::unimplemented("Not yet implemented"))
+                        }
                 }
             }
             (false, true) => {
@@ -147,7 +151,9 @@ fn generate_trait_methods(service: &Service, proto_path: &str) -> TokenStream {
 
                     #method_doc
                     async fn #name(&self, request: tonic::Request<#req_message>)
-                        -> Result<tonic::Response<Self::#stream>, tonic::Status>;
+                        -> Result<tonic::Response<Self::#stream>, tonic::Status> {
+                            Err(tonic::Status::unimplemented("Not yet implemented"))
+                        }
                 }
             }
             (true, true) => {
@@ -163,7 +169,9 @@ fn generate_trait_methods(service: &Service, proto_path: &str) -> TokenStream {
 
                     #method_doc
                     async fn #name(&self, request: tonic::Request<tonic::Streaming<#req_message>>)
-                        -> Result<tonic::Response<Self::#stream>, tonic::Status>;
+                        -> Result<tonic::Response<Self::#stream>, tonic::Status> {
+                            Err(tonic::Status::unimplemented("Not yet implemented"))
+                        }
                 }
             }
         };