diff --git a/make_libmodbus.sh b/make_libmodbus.sh
index 9f9fa3c..9e7a4fc 100755
--- a/make_libmodbus.sh
+++ b/make_libmodbus.sh
@@ -7,7 +7,7 @@ cd ./libmodbus/
 # reset to patch commit number
 git reset --hard 79a7c1ea82e5bb2e13c8efc77cb3e8a6d7368c58
 
-patch -c -p2 < ../mt.patch
+patch -p0 < ../mt.patch
 
 #./autogen.sh && ./configure --enable-static=yes --enable-shared=no && make
 ./autogen.sh && ./configure && make
diff --git a/modbus.js b/modbus.js
index 7dc307e..2fdc9a3 100644
--- a/modbus.js
+++ b/modbus.js
@@ -997,7 +997,7 @@ function createMasterRtu(a, con, cbs) {
 	api.destroy = function () {
 		isWorking = false;
 		
-		mb.close(ctx);
+		mb.close_mt(ctx);
 		mb.free(ctx);
 		
 		ctx = null;
diff --git a/mt.patch b/mt.patch
index 835e8fc..7ebcb3d 100644
--- a/mt.patch
+++ b/mt.patch
@@ -1,368 +1,313 @@
-diff -cr -x .git ./libmodbus.orig/src/modbus.c ./libmodbus/src/modbus.c
-*** ./libmodbus.orig/src/modbus.c	2014-02-07 22:46:00.000000000 +0100
---- ./libmodbus/src/modbus.c	2014-02-07 22:46:48.000000000 +0100
-***************
-*** 1457,1468 ****
---- 1457,1477 ----
-      ctx->backend->close(ctx);
-  }
-  
-+ void modbus_close_mt(modbus_t *ctx)
-+ {
-+     if (ctx == NULL)
-+         return;
-+ 	
-+     ctx->backend->close_mt(ctx);
-+ }
-+ 
-  void modbus_free(modbus_t *ctx)
-  {
-      if (ctx == NULL)
-          return;
-  
-      free(ctx->backend_data);
-+     free(ctx->mt_data);
-      free(ctx);
-  }
-  
-diff -cr -x .git ./libmodbus.orig/src/modbus.h ./libmodbus/src/modbus.h
-*** ./libmodbus.orig/src/modbus.h	2014-02-07 22:46:00.000000000 +0100
---- ./libmodbus/src/modbus.h	2014-02-07 22:46:48.000000000 +0100
-***************
-*** 169,174 ****
---- 169,175 ----
-  
-  EXPORT int modbus_connect(modbus_t *ctx);
-  EXPORT void modbus_close(modbus_t *ctx);
-+ EXPORT void modbus_close_mt(modbus_t *ctx);
-  
-  EXPORT void modbus_free(modbus_t *ctx);
-  
-diff -cr -x .git ./libmodbus.orig/src/modbus-private.h ./libmodbus/src/modbus-private.h
-*** ./libmodbus.orig/src/modbus-private.h	2014-02-07 22:46:00.000000000 +0100
---- ./libmodbus/src/modbus-private.h	2014-02-07 22:46:48.000000000 +0100
-***************
-*** 109,114 ****
---- 109,115 ----
-                                     const uint8_t *rsp, int rsp_length);
-      int (*connect) (modbus_t *ctx);
-      void (*close) (modbus_t *ctx);
-+     void (*close_mt) (modbus_t *ctx);
-      int (*flush) (modbus_t *ctx);
-      int (*select) (modbus_t *ctx, fd_set *rset, struct timeval *tv, int msg_length);
-  } modbus_backend_t;
-***************
-*** 124,129 ****
---- 125,131 ----
-      struct timeval byte_timeout;
-      const modbus_backend_t *backend;
-      void *backend_data;
-+     void *mt_data;
-  };
-  
-  void _modbus_init_common(modbus_t *ctx);
-diff -cr -x .git ./libmodbus.orig/src/modbus-rtu.c ./libmodbus/src/modbus-rtu.c
-*** ./libmodbus.orig/src/modbus-rtu.c	2014-02-07 22:46:00.000000000 +0100
---- ./libmodbus/src/modbus-rtu.c	2014-02-07 22:58:00.000000000 +0100
-***************
-*** 937,942 ****
---- 937,954 ----
-  #endif
-  }
-  
-+ void _modbus_rtu_close_mt(modbus_t *ctx)
-+ {
-+   ssize_t size;
-+ 	_modbus_rtu_close(ctx);
-+ 	
-+ 	modbus_rtu_mt_t *ctx_mt = ctx->mt_data;
-+ 	size = write(ctx_mt->mtp_w, "q", 1);
-+   if (size == -1)
-+     fprintf(stderr, "ERROR returned by write() (%s)\n",
-+       strerror(errno));
-+ }
-+ 
-  int _modbus_rtu_flush(modbus_t *ctx)
-  {
-  #if defined(_WIN32)
-***************
-*** 964,970 ****
-          return -1;
-      }
-  #else
-!     while ((s_rc = select(ctx->s+1, rset, NULL, NULL, tv)) == -1) {
-          if (errno == EINTR) {
-              if (ctx->debug) {
-                  fprintf(stderr, "A non blocked signal was caught\n");
---- 976,988 ----
-          return -1;
-      }
-  #else
-! 	/* Add pipe descriptor to select */
-! 	modbus_rtu_mt_t *ctx_mt = ctx->mt_data;
-! 	FD_SET(ctx_mt->mtp_r, rset);
-! 	
-! 	int max_n = (ctx->s > ctx_mt->mtp_r) ? ctx->s : ctx_mt->mtp_r;
-! 	
-!     while ((s_rc = select(max_n+1, rset, NULL, NULL, tv)) == -1) {
-          if (errno == EINTR) {
-              if (ctx->debug) {
-                  fprintf(stderr, "A non blocked signal was caught\n");
-***************
-*** 972,977 ****
---- 990,996 ----
-              /* Necessary after an error */
-              FD_ZERO(rset);
-              FD_SET(ctx->s, rset);
-+             FD_SET(ctx_mt->mtp_r, rset);
-          } else {
-              return -1;
-          }
-***************
-*** 983,989 ****
-          return -1;
-      }
-  #endif
-! 
-      return s_rc;
-  }
-  
---- 1002,1013 ----
-          return -1;
-      }
-  #endif
-! 	if (FD_ISSET(ctx_mt->mtp_r, rset)) {
-! 		/* Connection reset. */
-! 		errno = ECONNRESET;
-! 		return -1;
-! 	}
-! 	
-      return s_rc;
-  }
-  
-***************
-*** 1004,1009 ****
---- 1028,1034 ----
-      _modbus_rtu_pre_check_confirmation,
-      _modbus_rtu_connect,
-      _modbus_rtu_close,
-+     _modbus_rtu_close_mt,
-      _modbus_rtu_flush,
-      _modbus_rtu_select
-  };
-***************
-*** 1014,1019 ****
---- 1039,1045 ----
-  {
-      modbus_t *ctx;
-      modbus_rtu_t *ctx_rtu;
-+     modbus_rtu_mt_t *ctx_mt;
-      size_t dest_size;
-      size_t ret_size;
-  
-***************
-*** 1062,1067 ****
---- 1088,1107 ----
-  #endif
-  
-      ctx_rtu->confirmation_to_ignore = FALSE;
-+     
-+     /* Create pipe chanel */
-+     ctx->mt_data = (modbus_rtu_mt_t *) malloc(sizeof(modbus_rtu_mt_t));
-+     ctx_mt = (modbus_rtu_mt_t *)ctx->mt_data;
-+     
-+     int mtp[2];
-+     if (pipe(mtp) == -1) {
-+         fprintf(stderr, "ERROR Can't create pipe (%s)\n",
-+ 			strerror(errno));
-+ 		modbus_free(ctx);
-+         return NULL;
-+     }
-+     ctx_mt->mtp_r = mtp[0];
-+     ctx_mt->mtp_w = mtp[1];
-  
-      return ctx;
-  }
-diff -cr -x .git ./libmodbus.orig/src/modbus-rtu-private.h ./libmodbus/src/modbus-rtu-private.h
-*** ./libmodbus.orig/src/modbus-rtu-private.h	2014-02-07 22:46:00.000000000 +0100
---- ./libmodbus/src/modbus-rtu-private.h	2014-02-07 22:46:48.000000000 +0100
-***************
-*** 94,97 ****
---- 94,103 ----
-      int confirmation_to_ignore;
-  } modbus_rtu_t;
-  
-+ typedef struct _modbus_rtu_mt {
-+ 	/* Pipes for control in multithread */
-+     int mtp_r;
-+     int mtp_w;
-+ } modbus_rtu_mt_t;
-+ 
-  #endif /* _MODBUS_RTU_PRIVATE_H_ */
-diff -cr -x .git ./libmodbus.orig/src/modbus-tcp.c ./libmodbus/src/modbus-tcp.c
-*** ./libmodbus.orig/src/modbus-tcp.c	2014-02-07 22:46:00.000000000 +0100
---- ./libmodbus/src/modbus-tcp.c	2014-02-07 22:46:48.000000000 +0100
-***************
-*** 404,409 ****
---- 404,420 ----
-      close(ctx->s);
-  }
-  
-+ void _modbus_tcp_close_mt(modbus_t *ctx)
-+ {
-+ 	_modbus_tcp_close(ctx);
-+ 	
-+ 	modbus_tcp_mt_t *ctx_mt = ctx->mt_data;
-+ 	if (ctx_mt->lst_socket != -1) {
-+ 		shutdown(ctx_mt->lst_socket, SHUT_RDWR);
-+ 		close(ctx_mt->lst_socket);
-+ 	}
-+ }
-+ 
-  int _modbus_tcp_flush(modbus_t *ctx)
-  {
-      int rc;
-***************
-*** 448,453 ****
---- 459,465 ----
-      int yes;
-      struct sockaddr_in addr;
-      modbus_tcp_t *ctx_tcp = ctx->backend_data;
-+     modbus_tcp_mt_t *ctx_mt = ctx->mt_data;
-  
-  #ifdef OS_WIN32
-      if (_modbus_tcp_init_win32() == -1) {
-***************
-*** 481,486 ****
---- 493,500 ----
-          close(new_socket);
-          return -1;
-      }
-+     
-+     ctx_mt->lst_socket = new_socket;
-  
-      return new_socket;
-  }
-***************
-*** 495,500 ****
---- 509,515 ----
-      const char *service;
-      int new_socket;
-      modbus_tcp_pi_t *ctx_tcp_pi = ctx->backend_data;
-+     modbus_tcp_mt_t *ctx_mt = ctx->mt_data;
-  
-      if (ctx_tcp_pi->node[0] == 0)
-          node = NULL; /* == any */
-***************
-*** 577,582 ****
---- 592,599 ----
-      if (new_socket < 0) {
-          return -1;
-      }
-+     
-+     ctx_mt->lst_socket = new_socket;
-  
-      return new_socket;
-  }
-***************
-*** 671,676 ****
---- 688,694 ----
-      _modbus_tcp_pre_check_confirmation,
-      _modbus_tcp_connect,
-      _modbus_tcp_close,
-+     _modbus_tcp_close_mt,
-      _modbus_tcp_flush,
-      _modbus_tcp_select
-  };
-***************
-*** 693,698 ****
---- 711,717 ----
-      _modbus_tcp_pre_check_confirmation,
-      _modbus_tcp_pi_connect,
-      _modbus_tcp_close,
-+     _modbus_tcp_close_mt,
-      _modbus_tcp_flush,
-      _modbus_tcp_select
-  };
-***************
-*** 701,706 ****
---- 720,726 ----
-  {
-      modbus_t *ctx;
-      modbus_tcp_t *ctx_tcp;
-+     modbus_tcp_mt_t *ctx_mt;
-      size_t dest_size;
-      size_t ret_size;
-  
-***************
-*** 727,732 ****
---- 747,755 ----
-  
-      ctx->backend_data = (modbus_tcp_t *) malloc(sizeof(modbus_tcp_t));
-      ctx_tcp = (modbus_tcp_t *)ctx->backend_data;
-+     
-+     ctx->mt_data = (modbus_tcp_mt_t *) malloc(sizeof(modbus_tcp_mt_t));
-+     ctx_mt = (modbus_tcp_mt_t *)ctx->mt_data;
-  
-      dest_size = sizeof(char) * 16;
-      ret_size = strlcpy(ctx_tcp->ip, ip, dest_size);
-***************
-*** 746,751 ****
---- 769,776 ----
-  
-      ctx_tcp->port = port;
-      ctx_tcp->t_id = 0;
-+     
-+     ctx_mt->lst_socket = -1;
-  
-      return ctx;
-  }
-***************
-*** 755,760 ****
---- 780,786 ----
-  {
-      modbus_t *ctx;
-      modbus_tcp_pi_t *ctx_tcp_pi;
-+     modbus_tcp_mt_t *ctx_mt;
-      size_t dest_size;
-      size_t ret_size;
-  
-***************
-*** 768,773 ****
---- 794,802 ----
-  
-      ctx->backend_data = (modbus_tcp_pi_t *) malloc(sizeof(modbus_tcp_pi_t));
-      ctx_tcp_pi = (modbus_tcp_pi_t *)ctx->backend_data;
-+     
-+     ctx->mt_data = (modbus_tcp_mt_t *) malloc(sizeof(modbus_tcp_mt_t));
-+     ctx_mt = (modbus_tcp_mt_t *)ctx->mt_data;
-  
-      dest_size = sizeof(char) * _MODBUS_TCP_PI_NODE_LENGTH;
-      ret_size = strlcpy(ctx_tcp_pi->node, node, dest_size);
-***************
-*** 802,807 ****
---- 831,838 ----
-      }
-  
-      ctx_tcp_pi->t_id = 0;
-+     
-+     ctx_mt->lst_socket = -1;
-  
-      return ctx;
-  }
-diff -cr -x .git ./libmodbus.orig/src/modbus-tcp-private.h ./libmodbus/src/modbus-tcp-private.h
-*** ./libmodbus.orig/src/modbus-tcp-private.h	2014-02-07 22:46:00.000000000 +0100
---- ./libmodbus/src/modbus-tcp-private.h	2014-02-07 22:46:48.000000000 +0100
-***************
-*** 53,56 ****
---- 53,62 ----
-      char service[_MODBUS_TCP_PI_SERVICE_LENGTH];
-  } modbus_tcp_pi_t;
-  
-+ 
-+ typedef struct _modbus_tcp_mt {
-+ 	/* Main listen socket */
-+     int lst_socket;
-+ } modbus_tcp_mt_t;
-+ 
-  #endif /* _MODBUS_TCP_PRIVATE_H_ */
+diff --git src/modbus-private.h src/modbus-private.h
+index 7994459..799eccd 100644
+--- src/modbus-private.h
++++ src/modbus-private.h
+@@ -109,6 +109,7 @@ typedef struct _modbus_backend {
+                                    const uint8_t *rsp, int rsp_length);
+     int (*connect) (modbus_t *ctx);
+     void (*close) (modbus_t *ctx);
++    void (*close_mt) (modbus_t *ctx);
+     int (*flush) (modbus_t *ctx);
+     int (*select) (modbus_t *ctx, fd_set *rset, struct timeval *tv, int msg_length);
+ } modbus_backend_t;
+@@ -124,6 +125,7 @@ struct _modbus {
+     struct timeval byte_timeout;
+     const modbus_backend_t *backend;
+     void *backend_data;
++    void *mt_data;
+ };
+ 
+ void _modbus_init_common(modbus_t *ctx);
+diff --git src/modbus-rtu-private.h src/modbus-rtu-private.h
+index c8fdeab..4f20db4 100644
+--- src/modbus-rtu-private.h
++++ src/modbus-rtu-private.h
+@@ -94,4 +94,10 @@ typedef struct _modbus_rtu {
+     int confirmation_to_ignore;
+ } modbus_rtu_t;
+ 
++typedef struct _modbus_rtu_mt {
++	/* Pipes for control in multithread */
++    int mtp_r;
++    int mtp_w;
++} modbus_rtu_mt_t;
++
+ #endif /* _MODBUS_RTU_PRIVATE_H_ */
+diff --git src/modbus-rtu.c src/modbus-rtu.c
+index c41110e..60e7456 100644
+--- src/modbus-rtu.c
++++ src/modbus-rtu.c
+@@ -937,6 +937,20 @@ void _modbus_rtu_close(modbus_t *ctx)
+ #endif
+ }
+ 
++void _modbus_rtu_close_mt(modbus_t *ctx)
++{
++  ssize_t size;
++	_modbus_rtu_close(ctx);
++	
++	modbus_rtu_mt_t *ctx_mt = ctx->mt_data;
++	size = write(ctx_mt->mtp_w, "q", 1);
++  if (size == -1)
++    fprintf(stderr, "ERROR returned by write() (%s)\n",
++      strerror(errno));
++  close(ctx_mt->mtp_w);
++  close(ctx_mt->mtp_r);
++}
++
+ int _modbus_rtu_flush(modbus_t *ctx)
+ {
+ #if defined(_WIN32)
+@@ -964,7 +978,13 @@ int _modbus_rtu_select(modbus_t *ctx, fd_set *rset,
+         return -1;
+     }
+ #else
+-    while ((s_rc = select(ctx->s+1, rset, NULL, NULL, tv)) == -1) {
++	/* Add pipe descriptor to select */
++	modbus_rtu_mt_t *ctx_mt = ctx->mt_data;
++	FD_SET(ctx_mt->mtp_r, rset);
++	
++	int max_n = (ctx->s > ctx_mt->mtp_r) ? ctx->s : ctx_mt->mtp_r;
++	
++    while ((s_rc = select(max_n+1, rset, NULL, NULL, tv)) == -1) {
+         if (errno == EINTR) {
+             if (ctx->debug) {
+                 fprintf(stderr, "A non blocked signal was caught\n");
+@@ -972,6 +992,7 @@ int _modbus_rtu_select(modbus_t *ctx, fd_set *rset,
+             /* Necessary after an error */
+             FD_ZERO(rset);
+             FD_SET(ctx->s, rset);
++            FD_SET(ctx_mt->mtp_r, rset);
+         } else {
+             return -1;
+         }
+@@ -983,7 +1004,12 @@ int _modbus_rtu_select(modbus_t *ctx, fd_set *rset,
+         return -1;
+     }
+ #endif
+-
++	if (FD_ISSET(ctx_mt->mtp_r, rset)) {
++		/* Connection reset. */
++		errno = ECONNRESET;
++		return -1;
++	}
++	
+     return s_rc;
+ }
+ 
+@@ -1004,6 +1030,7 @@ const modbus_backend_t _modbus_rtu_backend = {
+     _modbus_rtu_pre_check_confirmation,
+     _modbus_rtu_connect,
+     _modbus_rtu_close,
++    _modbus_rtu_close_mt,
+     _modbus_rtu_flush,
+     _modbus_rtu_select
+ };
+@@ -1014,6 +1041,7 @@ modbus_t* modbus_new_rtu(const char *device,
+ {
+     modbus_t *ctx;
+     modbus_rtu_t *ctx_rtu;
++    modbus_rtu_mt_t *ctx_mt;
+     size_t dest_size;
+     size_t ret_size;
+ 
+@@ -1062,6 +1090,20 @@ modbus_t* modbus_new_rtu(const char *device,
+ #endif
+ 
+     ctx_rtu->confirmation_to_ignore = FALSE;
++    
++    /* Create pipe chanel */
++    ctx->mt_data = (modbus_rtu_mt_t *) malloc(sizeof(modbus_rtu_mt_t));
++    ctx_mt = (modbus_rtu_mt_t *)ctx->mt_data;
++    
++    int mtp[2];
++    if (pipe(mtp) == -1) {
++        fprintf(stderr, "ERROR Can't create pipe (%s)\n",
++			strerror(errno));
++		modbus_free(ctx);
++        return NULL;
++    }
++    ctx_mt->mtp_r = mtp[0];
++    ctx_mt->mtp_w = mtp[1];
+ 
+     return ctx;
+ }
+diff --git src/modbus-tcp-private.h src/modbus-tcp-private.h
+index 408d08a..8a2b43b 100644
+--- src/modbus-tcp-private.h
++++ src/modbus-tcp-private.h
+@@ -53,4 +53,10 @@ typedef struct _modbus_tcp_pi {
+     char service[_MODBUS_TCP_PI_SERVICE_LENGTH];
+ } modbus_tcp_pi_t;
+ 
++
++typedef struct _modbus_tcp_mt {
++	/* Main listen socket */
++    int lst_socket;
++} modbus_tcp_mt_t;
++
+ #endif /* _MODBUS_TCP_PRIVATE_H_ */
+diff --git src/modbus-tcp.c src/modbus-tcp.c
+index b3eae81..928b850 100644
+--- src/modbus-tcp.c
++++ src/modbus-tcp.c
+@@ -404,6 +404,17 @@ void _modbus_tcp_close(modbus_t *ctx)
+     close(ctx->s);
+ }
+ 
++void _modbus_tcp_close_mt(modbus_t *ctx)
++{
++	_modbus_tcp_close(ctx);
++	
++	modbus_tcp_mt_t *ctx_mt = ctx->mt_data;
++	if (ctx_mt->lst_socket != -1) {
++		shutdown(ctx_mt->lst_socket, SHUT_RDWR);
++		close(ctx_mt->lst_socket);
++	}
++}
++
+ int _modbus_tcp_flush(modbus_t *ctx)
+ {
+     int rc;
+@@ -448,6 +459,7 @@ int modbus_tcp_listen(modbus_t *ctx, int nb_connection)
+     int yes;
+     struct sockaddr_in addr;
+     modbus_tcp_t *ctx_tcp = ctx->backend_data;
++    modbus_tcp_mt_t *ctx_mt = ctx->mt_data;
+ 
+ #ifdef OS_WIN32
+     if (_modbus_tcp_init_win32() == -1) {
+@@ -481,6 +493,8 @@ int modbus_tcp_listen(modbus_t *ctx, int nb_connection)
+         close(new_socket);
+         return -1;
+     }
++    
++    ctx_mt->lst_socket = new_socket;
+ 
+     return new_socket;
+ }
+@@ -495,6 +509,7 @@ int modbus_tcp_pi_listen(modbus_t *ctx, int nb_connection)
+     const char *service;
+     int new_socket;
+     modbus_tcp_pi_t *ctx_tcp_pi = ctx->backend_data;
++    modbus_tcp_mt_t *ctx_mt = ctx->mt_data;
+ 
+     if (ctx_tcp_pi->node[0] == 0)
+         node = NULL; /* == any */
+@@ -577,6 +592,8 @@ int modbus_tcp_pi_listen(modbus_t *ctx, int nb_connection)
+     if (new_socket < 0) {
+         return -1;
+     }
++    
++    ctx_mt->lst_socket = new_socket;
+ 
+     return new_socket;
+ }
+@@ -671,6 +688,7 @@ const modbus_backend_t _modbus_tcp_backend = {
+     _modbus_tcp_pre_check_confirmation,
+     _modbus_tcp_connect,
+     _modbus_tcp_close,
++    _modbus_tcp_close_mt,
+     _modbus_tcp_flush,
+     _modbus_tcp_select
+ };
+@@ -693,6 +711,7 @@ const modbus_backend_t _modbus_tcp_pi_backend = {
+     _modbus_tcp_pre_check_confirmation,
+     _modbus_tcp_pi_connect,
+     _modbus_tcp_close,
++    _modbus_tcp_close_mt,
+     _modbus_tcp_flush,
+     _modbus_tcp_select
+ };
+@@ -701,6 +720,7 @@ modbus_t* modbus_new_tcp(const char *ip, int port)
+ {
+     modbus_t *ctx;
+     modbus_tcp_t *ctx_tcp;
++    modbus_tcp_mt_t *ctx_mt;
+     size_t dest_size;
+     size_t ret_size;
+ 
+@@ -727,6 +747,9 @@ modbus_t* modbus_new_tcp(const char *ip, int port)
+ 
+     ctx->backend_data = (modbus_tcp_t *) malloc(sizeof(modbus_tcp_t));
+     ctx_tcp = (modbus_tcp_t *)ctx->backend_data;
++    
++    ctx->mt_data = (modbus_tcp_mt_t *) malloc(sizeof(modbus_tcp_mt_t));
++    ctx_mt = (modbus_tcp_mt_t *)ctx->mt_data;
+ 
+     dest_size = sizeof(char) * 16;
+     ret_size = strlcpy(ctx_tcp->ip, ip, dest_size);
+@@ -746,6 +769,8 @@ modbus_t* modbus_new_tcp(const char *ip, int port)
+ 
+     ctx_tcp->port = port;
+     ctx_tcp->t_id = 0;
++    
++    ctx_mt->lst_socket = -1;
+ 
+     return ctx;
+ }
+@@ -755,6 +780,7 @@ modbus_t* modbus_new_tcp_pi(const char *node, const char *service)
+ {
+     modbus_t *ctx;
+     modbus_tcp_pi_t *ctx_tcp_pi;
++    modbus_tcp_mt_t *ctx_mt;
+     size_t dest_size;
+     size_t ret_size;
+ 
+@@ -768,6 +794,9 @@ modbus_t* modbus_new_tcp_pi(const char *node, const char *service)
+ 
+     ctx->backend_data = (modbus_tcp_pi_t *) malloc(sizeof(modbus_tcp_pi_t));
+     ctx_tcp_pi = (modbus_tcp_pi_t *)ctx->backend_data;
++    
++    ctx->mt_data = (modbus_tcp_mt_t *) malloc(sizeof(modbus_tcp_mt_t));
++    ctx_mt = (modbus_tcp_mt_t *)ctx->mt_data;
+ 
+     dest_size = sizeof(char) * _MODBUS_TCP_PI_NODE_LENGTH;
+     ret_size = strlcpy(ctx_tcp_pi->node, node, dest_size);
+@@ -802,6 +831,8 @@ modbus_t* modbus_new_tcp_pi(const char *node, const char *service)
+     }
+ 
+     ctx_tcp_pi->t_id = 0;
++    
++    ctx_mt->lst_socket = -1;
+ 
+     return ctx;
+ }
+diff --git src/modbus.c src/modbus.c
+index b555913..e08f7ae 100644
+--- src/modbus.c
++++ src/modbus.c
+@@ -1457,12 +1457,21 @@ void modbus_close(modbus_t *ctx)
+     ctx->backend->close(ctx);
+ }
+ 
++void modbus_close_mt(modbus_t *ctx)
++{
++    if (ctx == NULL)
++        return;
++	
++    ctx->backend->close_mt(ctx);
++}
++
+ void modbus_free(modbus_t *ctx)
+ {
+     if (ctx == NULL)
+         return;
+ 
+     free(ctx->backend_data);
++    free(ctx->mt_data);
+     free(ctx);
+ }
+ 
+diff --git src/modbus.h src/modbus.h
+index 399c41b..e31faf4 100644
+--- src/modbus.h
++++ src/modbus.h
+@@ -169,6 +169,7 @@ EXPORT int modbus_get_header_length(modbus_t *ctx);
+ 
+ EXPORT int modbus_connect(modbus_t *ctx);
+ EXPORT void modbus_close(modbus_t *ctx);
++EXPORT void modbus_close_mt(modbus_t *ctx);
+ 
+ EXPORT void modbus_free(modbus_t *ctx);
+