diff --git a/CHANGELOG b/CHANGELOG
index 00767413..f728b35d 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -23,6 +23,9 @@ HISTORY
 
   ++ Bugfixes:
 
+  2017-02-16: Simon Goldschmidt
+  * LWIP_NETCONN_FULLDUPLEX: fixed shutdown during write (bug #50274)
+
   2017-01-18: Dirk Ziegelmeier
   * Fix zero-copy RX, see bug bug #50064. PBUF_REFs were not supported as ARP requests.
 
diff --git a/src/api/api_msg.c b/src/api/api_msg.c
index e0a0a631..dd99c1e0 100644
--- a/src/api/api_msg.c
+++ b/src/api/api_msg.c
@@ -1784,25 +1784,28 @@ lwip_netconn_do_close(void *m)
 #if LWIP_NETCONN_FULLDUPLEX
       if (msg->msg.sd.shut & NETCONN_SHUT_WR) {
         /* close requested, abort running write */
-        sys_sem_t* op_completed_sem;
+        sys_sem_t* write_completed_sem;
         LWIP_ASSERT("msg->conn->current_msg != NULL", msg->conn->current_msg != NULL);
-        op_completed_sem = LWIP_API_MSG_SEM(msg->conn->current_msg);
+        write_completed_sem = LWIP_API_MSG_SEM(msg->conn->current_msg);
         msg->conn->current_msg->err = ERR_CLSD;
         msg->conn->current_msg = NULL;
         msg->conn->write_offset = 0;
         msg->conn->state = NETCONN_NONE;
+        state = NETCONN_NONE;
         NETCONN_SET_SAFE_ERR(msg->conn, ERR_CLSD);
-        sys_sem_signal(op_completed_sem);
+        sys_sem_signal(write_completed_sem);
       } else {
         LWIP_ASSERT("msg->msg.sd.shut == NETCONN_SHUT_RD", msg->msg.sd.shut == NETCONN_SHUT_RD);
         /* In this case, let the write continue and do not interfere with
            conn->current_msg or conn->state! */
         msg->err = tcp_shutdown(msg->conn->pcb.tcp, 1, 0);
       }
+    }
+    if (state == NETCONN_NONE) {
 #else /* LWIP_NETCONN_FULLDUPLEX */
       msg->err = ERR_INPROGRESS;
-#endif /* LWIP_NETCONN_FULLDUPLEX */
     } else {
+#endif /* LWIP_NETCONN_FULLDUPLEX */
       if (msg->msg.sd.shut & NETCONN_SHUT_RD) {
         /* Drain and delete mboxes */
         netconn_drain(msg->conn);