diff --git a/CHANGELOG b/CHANGELOG
index 6b8e349d..70632877 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -6,12 +6,16 @@ HISTORY
 
   ++ New features:
 
+  2015-02-11: Nick van Ijzendoorn
+  * opt.h, sockets.h/c: patch #7702 "Include ability to increase the socket number
+    with defined offset"
+
   2015-02-11: Frederick Baksik
-  opt.h, def.h, others: patch #8423 "arch/perf.h" should be made an optional item
+  * opt.h, def.h, others: patch #8423 "arch/perf.h" should be made an optional item
 
   2015-02-11: Simon Goldschmidt
   * api_msg.c, opt.h: started to implement fullduplex sockets/netconns
-   (note that this is highly unstable yet!)
+    (note that this is highly unstable yet!)
 
   2015-01-02: Simon Goldschmidt
   * tcp.c: tcp_kill_prio(): prefer nearly-closed connections (waiting for the
diff --git a/src/api/sockets.c b/src/api/sockets.c
index 0421c280..bba8e255 100644
--- a/src/api/sockets.c
+++ b/src/api/sockets.c
@@ -307,8 +307,10 @@ get_socket(int s)
 {
   struct lwip_sock *sock;
 
+  s -= LWIP_SOCKET_OFFSET;
+
   if ((s < 0) || (s >= NUM_SOCKETS)) {
-    LWIP_DEBUGF(SOCKETS_DEBUG, ("get_socket(%d): invalid\n", s));
+    LWIP_DEBUGF(SOCKETS_DEBUG, ("get_socket(%d): invalid\n", s + LWIP_SOCKET_OFFSET));
     set_errno(EBADF);
     return NULL;
   }
@@ -316,7 +318,7 @@ get_socket(int s)
   sock = &sockets[s];
 
   if (!sock->conn) {
-    LWIP_DEBUGF(SOCKETS_DEBUG, ("get_socket(%d): not active\n", s));
+    LWIP_DEBUGF(SOCKETS_DEBUG, ("get_socket(%d): not active\n", s + LWIP_SOCKET_OFFSET));
     set_errno(EBADF);
     return NULL;
   }
@@ -333,6 +335,7 @@ get_socket(int s)
 static struct lwip_sock *
 tryget_socket(int s)
 {
+  s -= LWIP_SOCKET_OFFSET;
   if ((s < 0) || (s >= NUM_SOCKETS)) {
     return NULL;
   }
@@ -374,7 +377,7 @@ alloc_socket(struct netconn *newconn, int accepted)
       sockets[i].errevent   = 0;
       sockets[i].err        = 0;
       sockets[i].select_waiting = 0;
-      return i;
+      return i + LWIP_SOCKET_OFFSET;
     }
     SYS_ARCH_UNPROTECT(lev);
   }
@@ -485,9 +488,9 @@ lwip_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
     sock_set_errno(sock, ENFILE);
     return -1;
   }
-  LWIP_ASSERT("invalid socket index", (newsock >= 0) && (newsock < NUM_SOCKETS));
+  LWIP_ASSERT("invalid socket index", (newsock >= LWIP_SOCKET_OFFSET) && (newsock < NUM_SOCKETS + LWIP_SOCKET_OFFSET));
   LWIP_ASSERT("newconn->callback == event_callback", newconn->callback == event_callback);
-  nsock = &sockets[newsock];
+  nsock = &sockets[newsock - LWIP_SOCKET_OFFSET];
 
   /* See event_callback: If data comes in right away after an accept, even
    * though the server task might not have created a new socket yet.
@@ -1157,7 +1160,7 @@ lwip_selscan(int maxfdp1, fd_set *readset_in, fd_set *writeset_in, fd_set *excep
 
   /* Go through each socket in each list to count number of sockets which
      currently match */
-  for(i = 0; i < maxfdp1; i++) {
+  for(i = LWIP_SOCKET_OFFSET; i < maxfdp1; i++) {
     void* lastdata = NULL;
     s16_t rcvevent = 0;
     u16_t sendevent = 0;
@@ -1270,7 +1273,7 @@ lwip_select(int maxfdp1, fd_set *readset, fd_set *writeset, fd_set *exceptset,
 
     /* Increase select_waiting for each socket we are interested in */
     maxfdp2 = maxfdp1;
-    for (i = 0; i < maxfdp1; i++) {
+    for (i = LWIP_SOCKET_OFFSET; i < maxfdp1; i++) {
       if ((readset && FD_ISSET(i, readset)) ||
           (writeset && FD_ISSET(i, writeset)) ||
           (exceptset && FD_ISSET(i, exceptset))) {
@@ -1313,7 +1316,7 @@ lwip_select(int maxfdp1, fd_set *readset, fd_set *writeset, fd_set *exceptset,
     }
 
     /* Decrease select_waiting for each socket we are interested in */
-    for (i = 0; i < maxfdp2; i++) {
+    for (i = LWIP_SOCKET_OFFSET; i < maxfdp2; i++) {
       if ((readset && FD_ISSET(i, readset)) ||
           (writeset && FD_ISSET(i, writeset)) ||
           (exceptset && FD_ISSET(i, exceptset))) {
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index e3895737..112fa2bc 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -1545,6 +1545,17 @@
 #define LWIP_POSIX_SOCKETS_IO_NAMES     1
 #endif
 
+/**
+ * LWIP_SOCKET_OFFSET==n: Increases the file descriptor number created by LwIP with n.
+ * This can be useful when there are multiple APIs which create file descriptors.
+ * When they all start with a different offset and you won't make them overlap you can
+ * re implement read/write/close/ioctl/fnctl to send the requested action to the right
+ * library (sharing select will need more work though).
+ */
+#ifndef LWIP_SOCKET_OFFSET
+#define LWIP_SOCKET_OFFSET              0
+#endif
+
 /**
  * LWIP_TCP_KEEPALIVE==1: Enable TCP_KEEPIDLE, TCP_KEEPINTVL and TCP_KEEPCNT
  * options processing. Note that TCP_KEEPIDLE and TCP_KEEPINTVL have to be set
diff --git a/src/include/lwip/sockets.h b/src/include/lwip/sockets.h
index 19766035..076d15de 100644
--- a/src/include/lwip/sockets.h
+++ b/src/include/lwip/sockets.h
@@ -378,18 +378,26 @@ typedef struct ip_mreq {
 
 /* FD_SET used for lwip_select */
 #ifndef FD_SET
-  #undef  FD_SETSIZE
-  /* Make FD_SETSIZE match NUM_SOCKETS in socket.c */
-  #define FD_SETSIZE    MEMP_NUM_NETCONN
-  #define FD_SET(n, p)  ((p)->fd_bits[(n)/8] |=  (1 << ((n) & 7)))
-  #define FD_CLR(n, p)  ((p)->fd_bits[(n)/8] &= ~(1 << ((n) & 7)))
-  #define FD_ISSET(n,p) ((p)->fd_bits[(n)/8] &   (1 << ((n) & 7)))
-  #define FD_ZERO(p)    memset((void*)(p),0,sizeof(*(p)))
+#undef  FD_SETSIZE
+/* Make FD_SETSIZE match NUM_SOCKETS in socket.c */
+#define FD_SETSIZE    MEMP_NUM_NETCONN
+#define FDSETSAFESET(n, p, code) do { \
+  if(((p) != NULL) && ((n) - LWIP_SOCKET_OFFSET < MEMP_NUM_NETCONN) && (((int)(n) - LWIP_SOCKET_OFFSET) >= 0)) { \
+  code; }} while(0)
+#define FDSETSAFEGET(n, p, code) (((p) != NULL) && ((n) - LWIP_SOCKET_OFFSET < MEMP_NUM_NETCONN) && (((int)(n) - LWIP_SOCKET_OFFSET) >= 0) ?\
+  (code) : 0)
+#define FD_SET(n, p)  FDSETSAFESET(n, p, (p)->fd_bits[((n)-LWIP_SOCKET_OFFSET)/8] |=  (1 << (((n)-LWIP_SOCKET_OFFSET) & 7)))
+#define FD_CLR(n, p)  FDSETSAFESET(n, p, (p)->fd_bits[((n)-LWIP_SOCKET_OFFSET)/8] &= ~(1 << (((n)-LWIP_SOCKET_OFFSET) & 7)))
+#define FD_ISSET(n,p) FDSETSAFEGET(n, p, (p)->fd_bits[((n)-LWIP_SOCKET_OFFSET)/8] &   (1 << (((n)-LWIP_SOCKET_OFFSET) & 7)))
+#define FD_ZERO(p)    memset((void*)(p), 0, sizeof(*(p)))
 
-  typedef struct fd_set {
-          unsigned char fd_bits [(FD_SETSIZE+7)/8];
-        } fd_set;
+typedef struct fd_set
+{
+  unsigned char fd_bits [(FD_SETSIZE+7)/8];
+} fd_set;
 
+#elif LWIP_SOCKET_OFFSET
+#error LWIP_SOCKET_OFFSET does not work with external FD_SET!
 #endif /* FD_SET */
 
 /** LWIP_TIMEVAL_PRIVATE: if you want to use the struct timeval provided