diff --git a/src/async.c b/src/async.c
index c27be20e..db25ce45 100644
--- a/src/async.c
+++ b/src/async.c
@@ -36,7 +36,7 @@ static int luv_new_async(lua_State* L) {
   int ret;
   luv_ctx_t* ctx = luv_context(L);
   luaL_checktype(L, 1, LUA_TFUNCTION);
-  handle = (uv_async_t*)luv_newuserdata(L, sizeof(*handle));
+  handle = (uv_async_t*)luv_newuserdata(L, uv_handle_size(UV_ASYNC));
   ret = uv_async_init(ctx->loop, handle, luv_async_cb);
   if (ret < 0) {
     lua_pop(L, 1);
diff --git a/src/check.c b/src/check.c
index 77f2ac53..25b533cb 100644
--- a/src/check.c
+++ b/src/check.c
@@ -24,7 +24,7 @@ static uv_check_t* luv_check_check(lua_State* L, int index) {
 
 static int luv_new_check(lua_State* L) {
   luv_ctx_t* ctx = luv_context(L);
-  uv_check_t* handle = (uv_check_t*)luv_newuserdata(L, sizeof(*handle));
+  uv_check_t* handle = (uv_check_t*)luv_newuserdata(L, uv_handle_size(UV_CHECK));
   int ret = uv_check_init(ctx->loop, handle);
   if (ret < 0) {
     lua_pop(L, 1);
diff --git a/src/fs_event.c b/src/fs_event.c
index 0bb4d633..1779e795 100644
--- a/src/fs_event.c
+++ b/src/fs_event.c
@@ -25,7 +25,7 @@ static uv_fs_event_t* luv_check_fs_event(lua_State* L, int index) {
 
 static int luv_new_fs_event(lua_State* L) {
   luv_ctx_t* ctx = luv_context(L);
-  uv_fs_event_t* handle = (uv_fs_event_t*)luv_newuserdata(L, sizeof(*handle));
+  uv_fs_event_t* handle = (uv_fs_event_t*)luv_newuserdata(L, uv_handle_size(UV_FS_EVENT));
   int ret = uv_fs_event_init(ctx->loop, handle);
   if (ret < 0) {
     lua_pop(L, 1);
diff --git a/src/fs_poll.c b/src/fs_poll.c
index e0c6d839..723b9c29 100644
--- a/src/fs_poll.c
+++ b/src/fs_poll.c
@@ -25,7 +25,7 @@ static uv_fs_poll_t* luv_check_fs_poll(lua_State* L, int index) {
 
 static int luv_new_fs_poll(lua_State* L) {
   luv_ctx_t* ctx = luv_context(L);
-  uv_fs_poll_t* handle = (uv_fs_poll_t*)luv_newuserdata(L, sizeof(*handle));
+  uv_fs_poll_t* handle = (uv_fs_poll_t*)luv_newuserdata(L, uv_handle_size(UV_FS_POLL));
   int ret = uv_fs_poll_init(ctx->loop, handle);
   if (ret < 0) {
     lua_pop(L, 1);
diff --git a/src/idle.c b/src/idle.c
index 725945e7..fa543ac5 100644
--- a/src/idle.c
+++ b/src/idle.c
@@ -24,7 +24,7 @@ static uv_idle_t* luv_check_idle(lua_State* L, int index) {
 
 static int luv_new_idle(lua_State* L) {
   luv_ctx_t* ctx = luv_context(L);
-  uv_idle_t* handle = (uv_idle_t*)luv_newuserdata(L, sizeof(*handle));
+  uv_idle_t* handle = (uv_idle_t*)luv_newuserdata(L, uv_handle_size(UV_IDLE));
   int ret = uv_idle_init(ctx->loop, handle);
   if (ret < 0) {
     lua_pop(L, 1);
diff --git a/src/pipe.c b/src/pipe.c
index 9dcb3835..38780ace 100644
--- a/src/pipe.c
+++ b/src/pipe.c
@@ -27,7 +27,7 @@ static int luv_new_pipe(lua_State* L) {
   int ipc, ret;
   luv_ctx_t* ctx = luv_context(L);
   ipc = luv_optboolean(L, 1, 0);
-  handle = (uv_pipe_t*)luv_newuserdata(L, sizeof(*handle));
+  handle = (uv_pipe_t*)luv_newuserdata(L, uv_handle_size(UV_NAMED_PIPE));
   ret = uv_pipe_init(ctx->loop, handle, ipc);
   if (ret < 0) {
     lua_pop(L, 1);
diff --git a/src/poll.c b/src/poll.c
index 1a8597d4..972de9cf 100644
--- a/src/poll.c
+++ b/src/poll.c
@@ -25,7 +25,7 @@ static uv_poll_t* luv_check_poll(lua_State* L, int index) {
 static int luv_new_poll(lua_State* L) {
   luv_ctx_t* ctx = luv_context(L);
   int fd = luaL_checkinteger(L, 1);
-  uv_poll_t* handle = (uv_poll_t*)luv_newuserdata(L, sizeof(*handle));
+  uv_poll_t* handle = (uv_poll_t*)luv_newuserdata(L, uv_handle_size(UV_POLL));
   int ret = uv_poll_init(ctx->loop, handle, fd);
   if (ret < 0) {
     lua_pop(L, 1);
@@ -38,7 +38,7 @@ static int luv_new_poll(lua_State* L) {
 static int luv_new_socket_poll(lua_State* L) {
   luv_ctx_t* ctx = luv_context(L);
   int fd = luaL_checkinteger(L, 1);
-  uv_poll_t* handle = (uv_poll_t*)luv_newuserdata(L, sizeof(*handle));
+  uv_poll_t* handle = (uv_poll_t*)luv_newuserdata(L, uv_handle_size(UV_POLL));
   int ret = uv_poll_init_socket(ctx->loop, handle, fd);
   if (ret < 0) {
     lua_pop(L, 1);
diff --git a/src/prepare.c b/src/prepare.c
index 6f8ae07b..ada86557 100644
--- a/src/prepare.c
+++ b/src/prepare.c
@@ -24,7 +24,7 @@ static uv_prepare_t* luv_check_prepare(lua_State* L, int index) {
 
 static int luv_new_prepare(lua_State* L) {
   luv_ctx_t* ctx = luv_context(L);
-  uv_prepare_t* handle = (uv_prepare_t*)luv_newuserdata(L, sizeof(*handle));
+  uv_prepare_t* handle = (uv_prepare_t*)luv_newuserdata(L, uv_handle_size(UV_PREPARE));
   int ret = uv_prepare_init(ctx->loop, handle);
   if (ret < 0) {
     lua_pop(L, 1);
diff --git a/src/process.c b/src/process.c
index 2fb37a99..6e429af8 100644
--- a/src/process.c
+++ b/src/process.c
@@ -277,7 +277,7 @@ static int luv_spawn(lua_State* L) {
   // the uv_process_t userdata doesn't get treated as the 3rd argument
   lua_settop(L, 3);
 
-  handle = (uv_process_t*)luv_newuserdata(L, sizeof(*handle));
+  handle = (uv_process_t*)luv_newuserdata(L, uv_handle_size(UV_PROCESS));
   handle->type = UV_PROCESS;
   handle->data = luv_setup_handle(L, ctx);
 
diff --git a/src/signal.c b/src/signal.c
index 4a1fa04a..2008d796 100644
--- a/src/signal.c
+++ b/src/signal.c
@@ -24,7 +24,7 @@ static uv_signal_t* luv_check_signal(lua_State* L, int index) {
 
 static int luv_new_signal(lua_State* L) {
   luv_ctx_t* ctx = luv_context(L);
-  uv_signal_t* handle = (uv_signal_t*)luv_newuserdata(L, sizeof(*handle));
+  uv_signal_t* handle = (uv_signal_t*)luv_newuserdata(L, uv_handle_size(UV_SIGNAL));
   int ret = uv_signal_init(ctx->loop, handle);
   if (ret < 0) {
     lua_pop(L, 1);
diff --git a/src/tcp.c b/src/tcp.c
index 51286a32..a6bb95d9 100644
--- a/src/tcp.c
+++ b/src/tcp.c
@@ -27,7 +27,7 @@ static int luv_new_tcp(lua_State* L) {
   int ret;
   luv_ctx_t* ctx = luv_context(L);
   lua_settop(L, 1);
-  handle = (uv_tcp_t*)luv_newuserdata(L, sizeof(*handle));
+  handle = (uv_tcp_t*)luv_newuserdata(L, uv_handle_size(UV_TCP));
 #if LUV_UV_VERSION_GEQ(1, 7, 0)
   if (lua_isnoneornil(L, 1)) {
     ret = uv_tcp_init(ctx->loop, handle);
diff --git a/src/timer.c b/src/timer.c
index 3c843751..c5943fe7 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -24,7 +24,7 @@ static uv_timer_t* luv_check_timer(lua_State* L, int index) {
 
 static int luv_new_timer(lua_State* L) {
   luv_ctx_t* ctx = luv_context(L);
-  uv_timer_t* handle = (uv_timer_t*) luv_newuserdata(L, sizeof(*handle));
+  uv_timer_t* handle = (uv_timer_t*) luv_newuserdata(L, uv_handle_size(UV_TIMER));
   int ret = uv_timer_init(ctx->loop, handle);
   if (ret < 0) {
     lua_pop(L, 1);
diff --git a/src/tty.c b/src/tty.c
index 93c1c1e9..5b6ac268 100644
--- a/src/tty.c
+++ b/src/tty.c
@@ -29,7 +29,7 @@ static int luv_new_tty(lua_State* L) {
   uv_file fd = luaL_checkinteger(L, 1);
   luaL_checktype(L, 2, LUA_TBOOLEAN);
   readable = lua_toboolean(L, 2);
-  handle = (uv_tty_t*)luv_newuserdata(L, sizeof(*handle));
+  handle = (uv_tty_t*)luv_newuserdata(L, uv_handle_size(UV_TTY));
   ret = uv_tty_init(ctx->loop, handle, fd, readable);
   if (ret < 0) {
     lua_pop(L, 1);
diff --git a/src/udp.c b/src/udp.c
index ae2fce2b..d017a0e0 100644
--- a/src/udp.c
+++ b/src/udp.c
@@ -25,7 +25,7 @@ static uv_udp_t* luv_check_udp(lua_State* L, int index) {
 static int luv_new_udp(lua_State* L) {
   luv_ctx_t* ctx = luv_context(L);
   lua_settop(L, 1);
-  uv_udp_t* handle = (uv_udp_t*)luv_newuserdata(L, sizeof(*handle));
+  uv_udp_t* handle = (uv_udp_t*)luv_newuserdata(L, uv_handle_size(UV_UDP));
   int ret;
 #if LUV_UV_VERSION_GEQ(1, 39, 0)
   // TODO: This default can potentially be increased, but it's