diff --git a/doc/lzmq.ldoc b/doc/lzmq.ldoc
index 24f1b70..582a314 100644
--- a/doc/lzmq.ldoc
+++ b/doc/lzmq.ldoc
@@ -165,6 +165,23 @@ function error:no             ()end
 -- @treturn string error name (e.g. "ETERM").
 function error:mnemo          ()end
 
+--- Get the error name
+-- This is synonym for `error:mnemo`
+--
+-- @treturn string error name (e.g. "ETERM").
+function error:name           ()end
+
+--- Get the error category
+--
+-- @treturn string error category. All lzmq errors has category `ZMQ`
+function error:category       ()end
+
+--- Get the error category
+-- This is synonym for `error:category`
+--
+-- @treturn string error category.
+function error:cat            ()end
+
 --- Get the error description
 -- 
 -- @treturn string result from `zmq_strerror`(e.g. "Context was terminated").
diff --git a/src/lua/lzmq/ffi.lua b/src/lua/lzmq/ffi.lua
index d611816..4344240 100644
--- a/src/lua/lzmq/ffi.lua
+++ b/src/lua/lzmq/ffi.lua
@@ -76,6 +76,8 @@ local function zerror(...) return Error:new(...) end
 do -- Error
 Error.__index = Error
 
+local ERROR_CATEGORY = "ZMQ"
+
 function Error:new(no)
   local o = setmetatable({
     errno = no or api.zmq_errno();
@@ -94,9 +96,19 @@ end
 function Error:mnemo()
   return api.zmq_mnemoerror(self.errno)
 end
+Error.name = Error.mnemo
+
+function Error:category()
+  return ERROR_CATEGORY
+end
+Error.cat = Error.category
+
+function Error:__eq(rhs)
+  return self:no() == rhs:no()
+end
 
 function Error:__tostring()
-  return string.format("[%s] %s (%d)", self:mnemo(), self:msg(), self:no())
+  return string.format("[%s][%s] %s (%d)", ERROR_CATEGORY, self:mnemo(), self:msg(), self:no())
 end
 
 end
diff --git a/src/zerror.c b/src/zerror.c
index daaf5b6..8bfdad3 100644
--- a/src/zerror.c
+++ b/src/zerror.c
@@ -15,6 +15,8 @@
 
 static const char* luazmq_err_getmnemo(int err);
 
+#define LZMQ_ERROR_CATEGORY "ZMQ"
+
 int luazmq_error_create(lua_State *L, int err){
   zerror *zerr = luazmq_newudata(L, zerror, LUAZMQ_ERROR);
   zerr->no = err;
@@ -22,7 +24,7 @@ int luazmq_error_create(lua_State *L, int err){
 }
 
 void luazmq_error_pushstring(lua_State *L, int err){
-  lua_pushfstring(L, "[%s] %s (%d)",
+  lua_pushfstring(L, "[" LZMQ_ERROR_CATEGORY "]""[%s] %s (%d)",
     luazmq_err_getmnemo(err),
     zmq_strerror(err),
     err
@@ -45,6 +47,12 @@ int luazmq_assert (lua_State *L) {
   return lua_gettop(L);
 }
 
+static int luazmq_err_cat(lua_State *L){
+  luazmq_geterror(L);
+  lua_pushliteral(L, LZMQ_ERROR_CATEGORY);
+  return 1;
+}
+
 static int luazmq_err_no(lua_State *L){
   zerror *zerr = luazmq_geterror(L);
   lua_pushinteger(L, zerr->no);
@@ -69,6 +77,13 @@ static int luazmq_err_tostring(lua_State *L){
   return 1;
 }
 
+static int luazmq_err_equal(lua_State *L){
+  zerror *lhs = luazmq_geterror_at(L, 1);
+  zerror *rhs = luazmq_geterror_at(L, 2);
+  lua_pushboolean(L, (lhs->no == rhs->no)?1:0);
+  return 1;
+}
+
 static const char* luazmq_err_getmnemo(int err){
 #define RETURN_IF(E) case E: return #E;
 
@@ -144,7 +159,11 @@ static const struct luaL_Reg luazmq_err_methods[] = {
   {"no",              luazmq_err_no               },
   {"msg",             luazmq_err_msg              },
   {"mnemo",           luazmq_err_mnemo            },
+  {"name",            luazmq_err_mnemo            },
+  {"cat",             luazmq_err_cat              },
+  {"category",        luazmq_err_cat              },
   {"__tostring",      luazmq_err_tostring         },
+  {"__eq",            luazmq_err_equal            },
 
   {NULL,NULL}
 };
diff --git a/test/utest.lua b/test/utest.lua
index 678e244..4633dfc 100644
--- a/test/utest.lua
+++ b/test/utest.lua
@@ -204,10 +204,14 @@ function test_error()
   local err = zmq.error(zmq.errors.EAGAIN)
   assert_equal(zmq.errors.EAGAIN, err:no())
   assert_equal("EAGAIN", err:mnemo())
+  assert_equal("EAGAIN", err:name())
+  assert_equal("ZMQ", err:cat())
+  assert_equal("ZMQ", err:category())
   local str_err = tostring(err)
   local ok, msg = pcall( zassert, false, err )
   assert_false(ok)
   assert_equal(str_err, msg)
+  assert_equal(err, zmq.error(zmq.errors.EAGAIN))
 end
 
 function test_interface()