diff --git a/lib/searpc-named-pipe-transport.c b/lib/searpc-named-pipe-transport.c
index 8297286..a2291cd 100644
--- a/lib/searpc-named-pipe-transport.c
+++ b/lib/searpc-named-pipe-transport.c
@@ -10,6 +10,7 @@
   #include <unistd.h>
 #endif // !defined(WIN32)
 
+#include <glib.h>
 #include <glib/gstdio.h>
 #include <jansson.h>
 
@@ -213,15 +214,15 @@ static void* named_pipe_client_handler(void *arg)
     // SearpcNamedPipeServer *server = data->server;
     SearpcNamedPipe connfd = data->connfd;
 
-    size_t len;
-    size_t bufsize = 4096;
+    guint32 len;
+    guint32 bufsize = 4096;
     char *buf = g_malloc(bufsize);
 
     g_debug ("start to serve on pipe client\n");
 
     while (1) {
         len = 0;
-        if (pipe_read_n(connfd, &len, sizeof(uint32_t)) < 0) {
+        if (pipe_read_n(connfd, &len, sizeof(guint32)) < 0) {
             g_warning("failed to read rpc request size: %s", strerror(errno));
             break;
         }
@@ -247,12 +248,13 @@ static void* named_pipe_client_handler(void *arg)
             break;
         }
 
-        size_t ret_len;
+        gsize ret_len;
         char *ret_str = searpc_server_call_function (service, body, strlen(body), &ret_len);
         g_free (service);
         g_free (body);
 
-        if (pipe_write_n(connfd, &ret_len, sizeof(uint32_t)) < 0) {
+        len = (guint32)ret_len;
+        if (pipe_write_n(connfd, &len, sizeof(guint32)) < 0) {
             g_warning("failed to send rpc response(%s): %s", ret_str, strerror(errno));
             g_free (ret_str);
             break;
@@ -344,16 +346,15 @@ char *searpc_named_pipe_send(void *arg, const gchar *fcall_str,
     SearpcNamedPipeClient *client = data->client;
 
     char *json_str = request_to_json(data->service, fcall_str, fcall_len);
-    size_t json_len = strlen(json_str);
+    guint32 len = (guint32)strlen(json_str);
 
-    uint32_t len = json_len;
-    if (pipe_write_n(client->pipe_fd, &len, sizeof(uint32_t)) < 0) {
+    if (pipe_write_n(client->pipe_fd, &len, sizeof(guint32)) < 0) {
         g_warning("failed to send rpc call: %s", strerror(errno));
         free (json_str);
         return NULL;
     }
 
-    if (pipe_write_n(client->pipe_fd, json_str, json_len) < 0) {
+    if (pipe_write_n(client->pipe_fd, json_str, len) < 0) {
         g_warning("failed to send rpc call: %s", strerror(errno));
         free (json_str);
         return NULL;
@@ -361,7 +362,7 @@ char *searpc_named_pipe_send(void *arg, const gchar *fcall_str,
 
     free (json_str);
 
-    if (pipe_read_n(client->pipe_fd, &len, sizeof(uint32_t)) < 0) {
+    if (pipe_read_n(client->pipe_fd, &len, sizeof(guint32)) < 0) {
         g_warning("failed to read rpc response: %s", strerror(errno));
         return NULL;
     }