diff --git a/CHANGELOG b/CHANGELOG
index 1dc727d5..6f5d31d2 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -19,6 +19,10 @@ HISTORY
 
   ++ New features:
 
+  2010-02-12: Simon Goldschmidt
+  * sockets.c/.h: Added a minimal version of posix fctl() to have a
+    standardised way to set O_NONBLOCK for nonblocking sockets.
+
   2010-02-12: Simon Goldschmidt
   * dhcp.c/.h, autoip.c/.h: task #10139 (Prefer statically allocated
     memory): added autoip_set_struct() and dhcp_set_struct() to let autoip
diff --git a/src/api/sockets.c b/src/api/sockets.c
index 5f145eda..1162ece8 100644
--- a/src/api/sockets.c
+++ b/src/api/sockets.c
@@ -2045,4 +2045,33 @@ lwip_ioctl(int s, long cmd, void *argp)
   } /* switch (cmd) */
 }
 
+/** A minimal implementation of fcntl.
+ * Currently only the commands F_GETFL and F_SETFL are implemented.
+ * Only the flag O_NONBLOCK is implemented.
+ */
+int
+lwip_fcntl(int s, int cmd, int val)
+{
+  struct lwip_socket *sock = get_socket(s);
+  int ret = -1;
+
+  if (!sock || !sock->conn) {
+    return -1;
+  }
+
+  switch (cmd) {
+  case F_GETFL:
+    ret = netconn_is_nonblocking(sock->conn) ? O_NONBLOCK : 0;
+    break;
+  case F_SETFL:
+    if ((val & ~O_NONBLOCK) == 0) {
+      /* only O_NONBLOCK, all other bits are zero */
+      netconn_set_nonblocking(sock->conn, val & O_NONBLOCK);
+      ret = 0;
+    }
+    break;
+  }
+  return ret;
+}
+
 #endif /* LWIP_SOCKET */
diff --git a/src/include/lwip/sockets.h b/src/include/lwip/sockets.h
index 3aa3a9b9..975b725e 100644
--- a/src/include/lwip/sockets.h
+++ b/src/include/lwip/sockets.h
@@ -262,6 +262,22 @@ typedef struct ip_mreq {
 #define SIOCATMARK  _IOR('s',  7, unsigned long)  /* at oob mark? */
 #endif
 
+/* commands for fnctl */
+#ifndef F_GETFL
+#define F_GETFL 3
+#endif
+#ifndef F_SETFL
+#define F_SETFL 4
+#endif
+
+/* File status flags and file access modes for fnctl,
+   these are bits in an int. */
+#ifndef O_NONBLOCK
+#define O_NONBLOCK  1 /* nonblocking I/O */
+#endif
+#ifndef O_NDELAY
+#define O_NDELAY    1 /* same as O_NONBLOCK, for compatibility */
+#endif
 
 /* FD_SET used for lwip_select */
 #ifndef FD_SET
@@ -316,6 +332,7 @@ int lwip_write(int s, const void *dataptr, size_t size);
 int lwip_select(int maxfdp1, fd_set *readset, fd_set *writeset, fd_set *exceptset,
                 struct timeval *timeout);
 int lwip_ioctl(int s, long cmd, void *argp);
+int lwip_fcntl(int s, int cmd, int val);
 
 #if LWIP_COMPAT_SOCKETS
 #define accept(a,b,c)         lwip_accept(a,b,c)