diff --git a/examples/proto.lua b/examples/proto.lua
index bbc7ee94..5cf85b11 100644
--- a/examples/proto.lua
+++ b/examples/proto.lua
@@ -7,7 +7,6 @@ local proto = sprotoparser.parse [[
 }
 
 handshake 1 {
-	request {}
 	response {
 		msg 0  : string
 	}
diff --git a/lualib-src/sproto/lsproto.c b/lualib-src/sproto/lsproto.c
index c2ef29e7..602f86e9 100644
--- a/lualib-src/sproto/lsproto.c
+++ b/lualib-src/sproto/lsproto.c
@@ -422,14 +422,16 @@ lprotocol(lua_State *L) {
 	}
 	struct sproto_type * request = sproto_protoquery(sp, tag, SPROTO_REQUEST);
 	if (request == NULL) {
-		return 0;
+		lua_pushnil(L);
+	} else {
+		lua_pushlightuserdata(L, request);
 	}
-	lua_pushlightuserdata(L, request);
 	struct sproto_type * response = sproto_protoquery(sp, tag, SPROTO_RESPONSE);
 	if (response == NULL) {
-		return 2;
+		lua_pushnil(L);
+	} else {
+		lua_pushlightuserdata(L, response);
 	}
-	lua_pushlightuserdata(L, response);
 	return 3;
 }
 
diff --git a/lualib-src/sproto/sproto.c b/lualib-src/sproto/sproto.c
index c701d092..0f519d14 100644
--- a/lualib-src/sproto/sproto.c
+++ b/lualib-src/sproto/sproto.c
@@ -329,10 +329,13 @@ import_protocol(struct sproto *s, struct protocol *p, const uint8_t * stream) {
 	p->p[SPROTO_REQUEST] = NULL;
 	p->p[SPROTO_RESPONSE] = NULL;
 	int i;
-	for (i=0;i<fn;i++) {
+	int tag = 0;
+	for (i=0;i<fn;i++,tag++) {
 		int value = toword(stream + SIZEOF_FIELD * i);
-		if (value & 1)
-			return NULL;
+		if (value & 1) {
+			tag += (value-1)/2;
+			continue;
+		}
 		value = value/2 - 1;
 		switch (i) {
 		case 0:	// name
@@ -362,7 +365,7 @@ import_protocol(struct sproto *s, struct protocol *p, const uint8_t * stream) {
 		}
 	}
 
-	if (p->name == NULL || p->tag<0 || p->p[SPROTO_REQUEST] == NULL) {
+	if (p->name == NULL || p->tag<0) {
 		return NULL;
 	}
 
diff --git a/lualib/sproto.lua b/lualib/sproto.lua
index 423a5611..a6180b0b 100644
--- a/lualib/sproto.lua
+++ b/lualib/sproto.lua
@@ -126,11 +126,19 @@ function rpc:dispatch(...)
 	if header.type then
 		-- request
 		local proto = queryproto(self.__proto, header.type)
-		local result = core.decode(proto.request, content)
-		if header_tmp.session then
-			return "REQUEST", proto.name, result, gen_response(self, proto.response, header_tmp.session)
+		if proto.request then
+			local result = core.decode(proto.request, content)
+			if header_tmp.session then
+				return "REQUEST", proto.name, result, gen_response(self, proto.response, header_tmp.session)
+			else
+				return "REQUEST", proto.name, result
+			end
 		else
-			return "REQUEST", proto.name, result
+			if header_tmp.session then
+				return "REQUEST", proto.name, nil, gen_response(self, proto.response, header_tmp.session)
+			else
+				return "REQUEST", proto.name
+			end
 		end
 	else
 		-- response
diff --git a/lualib/sprotoparser.lua b/lualib/sprotoparser.lua
index 1b9dcfcd..f6b24399 100644
--- a/lualib/sprotoparser.lua
+++ b/lualib/sprotoparser.lua
@@ -271,30 +271,35 @@ local function packtype(name, t, alltypes)
 end
 
 local function packproto(name, p, alltypes)
-	if p.request == nil then
-		error(string.format("Protocol %s need request", name))
+--	if p.request == nil then
+--		error(string.format("Protocol %s need request", name))
+--	end
+	if p.request then
+		local request = alltypes[p.request]
+		if request == nil then
+			error(string.format("Protocol %s request type %s not found", name, p.request))
+		end
 	end
-	local request = alltypes[p.request]
-	if request == nil then
-		error(string.format("Protocol %s request type %s not found", name, p.request))
-	end
-	local tmp
-	if p.response then
-		tmp = {
-			"\4\0",	-- 4 fields
-			"\0\0",	-- name (id=0, ref=0)
-			packvalue(p.tag),	-- tag (tag=1)
-			packvalue(alltypes[p.request]),	-- request typename (tag=2)
-			packvalue(alltypes[p.response]),  -- response typename (tag=3)
-		}
+	local tmp = {
+		"\4\0",	-- 4 fields
+		"\0\0",	-- name (id=0, ref=0)
+		packvalue(p.tag),	-- tag (tag=1)
+	}
+	if p.request == nil and p.response == nil then
+		tmp[1] = "\2\0"
 	else
-		tmp = {
-			"\3\0",	-- 3 fields
-			"\0\0",	-- name (id=0, ref=0)
-			packvalue(p.tag),	-- tag (tag=1)
-			packvalue(alltypes[p.request]),	-- request typename (tag=2)
-		}
+		if p.request then
+			table.insert(tmp, packvalue(alltypes[p.request])) -- request typename (tag=2)
+		else
+			table.insert(tmp, "\1\0")
+		end
+		if p.response then
+			table.insert(tmp, packvalue(alltypes[p.response])) -- request typename (tag=3)
+		else
+			tmp[1] = "\3\0"
+		end
 	end
+
 	table.insert(tmp, packbytes(name))
 
 	return packbytes(table.concat(tmp))