diff --git a/src/generators/ts_c.rs b/src/generators/ts_c.rs
index 3cb0276..770f672 100644
--- a/src/generators/ts_c.rs
+++ b/src/generators/ts_c.rs
@@ -34,10 +34,10 @@ pub fn method_args(method: &crate::data::MethodTy) -> String {
 }
 
 pub fn method_ret(method: &crate::data::MethodTy) -> String {
-    if method.ret_stream || method.ret.is_none() {
+    if method.ret_stream {
         String::new()
     } else {
-        format!(": Promise<{}>", ty_to_str(method.ret.as_ref().unwrap()))
+        format!(": Promise<{}>", method.ret.as_ref().map(ty_to_str).unwrap_or("void".into()))
     }
 }
 
diff --git a/templates/cpp_server.rs.cxx b/templates/cpp_server.rs.cxx
index 8866f64..fcc789b 100644
--- a/templates/cpp_server.rs.cxx
+++ b/templates/cpp_server.rs.cxx
@@ -89,8 +89,9 @@ void mrpc::MRPCServer::msg_handler(const std::shared_ptr<restbed::Session> __c,
             }
 @for (name, ty) in m.args.iter().map(|a| (&a.name, ty_to_str(&a.ty))) {            @ty @name; @name << json_get(__data, "@name");
             }
-            @if m.ret_stream || m.ret.is_none() {@(s.name)_@(m.name)(@call_args(m));}
-            else {send_msg(__c, @(s.name)_@(m.name)(@call_args(m)));}
+            @if m.ret_stream {@(s.name)_@(m.name)(@call_args(m));}
+            else if m.ret.is_some() {send_msg(__c, @(s.name)_@(m.name)(@call_args(m)));}
+            else {@(s.name)_@(m.name)(@call_args(m)); send_msg(__c, nullptr);}
         @}}
         else @{ throw std::exception@{@}; @}
     @}}
diff --git a/templates/cpp_server_json.rs.cxx b/templates/cpp_server_json.rs.cxx
index 5360aac..effd6a9 100644
--- a/templates/cpp_server_json.rs.cxx
+++ b/templates/cpp_server_json.rs.cxx
@@ -24,6 +24,10 @@ mrpc::MRPCJWriter& operator>>(const mrpc::@e.name &v, mrpc::MRPCJWriter &w) @{
     return w;
 @}
 }
+inline mrpc::MRPCJWriter& operator>>(const std::nullptr_t &, mrpc::MRPCJWriter &w) @{
+    w.Null();
+    return w;
+@}
 
 template<typename T>
 inline std::vector<T>& operator<<(std::vector<T> &v, const rapidjson::Value &j);
diff --git a/templates/typescript_client.rs.ts b/templates/typescript_client.rs.ts
index 505918b..45f09bd 100644
--- a/templates/typescript_client.rs.ts
+++ b/templates/typescript_client.rs.ts
@@ -36,8 +36,10 @@ export class MRPCConnector @{
         else if m.ret_stream {fetchEventSource(this.url, @{
             method: 'POST',
             body: JSON.stringify(__msg),
-            onmessage: __e => __cbk(JSON.parse(__e.data))
-        @});} else {fetch(this.url, @{method: 'POST', body: JSON.stringify(__msg)@});}
+            onmessage: __e => __cbk(JSON.parse(__e.data)),
+            onerror: __e => @{throw __e;@},
+            onclose: () => __cbk(null)
+        @});} else {return fetch(this.url, @{method: 'POST', body: JSON.stringify(__msg)@}).then(__r => @{@});}
     @}
 }}
 @}