diff --git a/apps/discard.c b/apps/discard.c
index 288d210..bfd63e3 100644
--- a/apps/discard.c
+++ b/apps/discard.c
@@ -13,6 +13,8 @@ static void discard_server (int sock)
   int host, connection, size;
   char buffer[1000];
 
+  fprintf (stderr, "Listening to socket %d.\n", sock);
+
   size = 8;
   if (ncp_listen (sock, &size, &host, &connection) == -1) {
     fprintf (stderr, "NCP listen error.\n");
@@ -22,12 +24,21 @@ static void discard_server (int sock)
 
   for (;;) {
     size = sizeof buffer;
-    if (ncp_read (connection, buffer, &size) == -1)
+    if (ncp_read (connection, buffer, &size) == -1) {
       fprintf (stderr, "NCP read error.\n");
-    if (size <= 0)
-      return;
+      if (ncp_close (connection) == -1)
+        fprintf (stderr, "NCP close error.\n");
+      break;
+    }
+    if (size == 0)
+      break;
     fprintf (stderr, "Read %d octets.\n", size);
   }
+
+  if (ncp_unlisten (sock) == -1) {
+    fprintf (stderr, "NCP unlisten error.\n");
+    exit (1);
+  }
 }
 
 static void usage (const char *argv0)
diff --git a/apps/echo.c b/apps/echo.c
index 1428da0..04cd7da 100644
--- a/apps/echo.c
+++ b/apps/echo.c
@@ -29,37 +29,45 @@ static void echo_client (int host, int sock)
 
   for (;;) {
     size = read (0, buffer, sizeof buffer);
-    if (size == -1)
+    if (size < 0)
       fprintf (stderr, "Read error.\n");
-    if (size <= 0)
-      goto end;
+    if (size <= 0) {
+      if (ncp_close (connection) == -1)
+        fprintf (stderr, "NCP close error.\n");
+      return;
+    }
     for (ptr = buffer; size > 0; ptr += n, size -= n) {
       n = size;
-      if (ncp_write (connection, ptr, &n) == -1)
+      if (ncp_write (connection, ptr, &n) == -1) {
         fprintf (stderr, "NCP read error.\n");
-      if (n <= 0)
-        goto end;
+        if (ncp_close (connection) == -1)
+          fprintf (stderr, "NCP close error.\n");
+        return;
+      }
+      if (n == 0)
+        return;
     }
 
     n = sizeof buffer;
-    if (ncp_read (connection, buffer, &n) == -1)
+    if (ncp_read (connection, buffer, &n) == -1) {
       fprintf (stderr, "NCP read error.\n");
-    if (n <= 0)
-      goto end;
+      if (ncp_close (connection) == -1)
+        fprintf (stderr, "NCP close error.\n");
+      return;
+    }
+    if (n == 0)
+      return;
     for (ptr = buffer; n > 0; n -= size) {
       size = write (1, ptr, n);
-      if (size < 0)
+      if (size < 0) {
         fprintf (stderr, "Write error.\n");
+        if (ncp_close (connection) == -1)
+          fprintf (stderr, "NCP close error.\n");
+      }
       if (size <= 0)
-        goto end;
+        return;
     }
   }
-
- end:
-  if (ncp_close (connection) == -1) {
-    fprintf (stderr, "NCP close error.\n");
-    exit (1);
-  }
 }
 
 static void echo_server (int sock)
@@ -67,6 +75,8 @@ static void echo_server (int sock)
   int host, connection, size, n;
   char buffer[1000], *ptr;
 
+  fprintf (stderr, "Listening to socket %d.\n", sock);
+
   size = 8;
   if (ncp_listen (sock, &size, &host, &connection) == -1) {
     fprintf (stderr, "NCP listen error.\n");
@@ -76,18 +86,32 @@ static void echo_server (int sock)
 
   for (;;) {
     size = sizeof buffer;
-    if (ncp_read (connection, buffer, &size) == -1)
+    if (ncp_read (connection, buffer, &size) == -1) {
       fprintf (stderr, "NCP read error.\n");
-    if (size <= 0)
-      return;
+      if (ncp_close (connection) == -1)
+        fprintf (stderr, "NCP close error.\n");
+      goto end;
+    }
+    if (size == 0)
+      goto end;
     for (ptr = buffer; size > 0; ptr += n, size -= n) {
       n = size;
-      if (ncp_write (connection, ptr, &n) == -1)
+      if (ncp_write (connection, ptr, &n) == -1) {
         fprintf (stderr, "NCP read error.\n");
-      if (n <= 0)
-        return;
+        if (ncp_close (connection) == -1)
+          fprintf (stderr, "NCP close error.\n");
+        goto end;
+      }
+      if (n == 0)
+        goto end;
     }
   }
+
+ end:
+  if (ncp_unlisten (sock) == -1) {
+    fprintf (stderr, "NCP unlisten error.\n");
+    exit (1);
+  }
 }
 
 static void usage (const char *argv0)
diff --git a/apps/finger.c b/apps/finger.c
index cfcd607..a745b1c 100644
--- a/apps/finger.c
+++ b/apps/finger.c
@@ -46,14 +46,24 @@ int main (int argc, char **argv)
                    argc == 3 ? argv[2] : "");
   if (ncp_write (connection, command, &size) == -1) {
     fprintf (stderr, "NCP write error.\n");
+    if (ncp_close (connection) == -1)
+      fprintf (stderr, "NCP close error.\n");
+    exit (1);
+  }
+  if (size == 0) {
+    fprintf (stderr, "Connection closed.\n");
     exit (1);
   }
 
   size = sizeof reply;
   if (ncp_read (connection, reply, &size) == -1) {
     fprintf (stderr, "NCP read error.\n");
+    if (ncp_close (connection) == -1)
+      fprintf (stderr, "NCP close error.\n");
     exit (1);
   }
+  if (size == 0)
+    exit (0);
 
   write (1, reply, size);
 
diff --git a/apps/finser.c b/apps/finser.c
index 4267a47..386b79b 100644
--- a/apps/finser.c
+++ b/apps/finser.c
@@ -5,6 +5,8 @@
 #include <string.h>
 #include "ncp.h"
 
+#define SOCKET  0117
+
 int main (int argc, char **argv)
 {
   char command[1000];
@@ -25,16 +27,25 @@ int main (int argc, char **argv)
     exit (1);
   }
 
+  fprintf (stderr, "Listening to socket %d.\n", SOCKET);
+
   size = 8;
-  if (ncp_listen (0117, &size, &host, &connection) == -1) {
+  if (ncp_listen (SOCKET, &size, &host, &connection) == -1) {
     fprintf (stderr, "NCP listen error.\n");
     exit (1);
   }
+  fprintf (stderr, "Connection from host %03o.\n", host);
 
   size = sizeof command;
   if (ncp_read (connection, command, &size) == -1) {
     fprintf (stderr, "NCP read error.\n");
-    exit (1);
+    if (ncp_close (connection) == -1)
+      fprintf (stderr, "NCP close error.\n");
+    goto unlisten;
+  }
+  if (size == 0) {
+    fprintf (stderr, "Connection closed.\n");
+    goto unlisten;
   }
   command[size] = 0;
 
@@ -42,14 +53,17 @@ int main (int argc, char **argv)
             "Sample response from Finger server.\r\n"
             "Data from client was: \"%s\".\r\n", command);
   size = strlen (reply);
-  if (ncp_write (connection, reply, &size) == -1) {
+  if (ncp_write (connection, reply, &size) == -1)
     fprintf (stderr, "NCP write error.\n");
-    exit (1);
-  }
 
-  if (ncp_close (connection) == -1) {
+  if (size != 0 && ncp_close (connection) == -1)
     fprintf (stderr, "NCP close error.\n");
+
+ unlisten:
+  if (ncp_unlisten (SOCKET) == -1) {
+    fprintf (stderr, "NCP unlisten error.\n");
     exit (1);
   }
 
+  return 0;
 }
diff --git a/apps/gateway.c b/apps/gateway.c
index 1233fc4..33f8a61 100644
--- a/apps/gateway.c
+++ b/apps/gateway.c
@@ -140,6 +140,8 @@ static void tcp_to_ncp (const char *port, const char *host, const char *sock)
   int connection, foreign_port;
   int fd, s, size;
 
+  fprintf (stderr, "Listening to port %s.\n", port);
+
   s = inet_server (port);
   fd = inet_accept (s, &foreign_host, &foreign_port);
   fprintf (stderr, "Connection from host %s on port %d.\n",
@@ -161,6 +163,7 @@ static void tcp_to_ncp (const char *port, const char *host, const char *sock)
     exit (1);
   }
 
+  fprintf (stderr, "Forwarding to host %d socket %d.\n", ncp_host, ncp_sock);
   transport (fd, connection);
 
   if (ncp_close (connection) == -1) {
@@ -173,6 +176,8 @@ static void ncp_to_tcp (int sock, const char *host, const char *port)
 {
   int fd, ncp_host, connection, size;
 
+  fprintf (stderr, "Listening to socket %d.\n", sock);
+
   size = 8;
   if (ncp_listen (sock, &size, &ncp_host, &connection) == -1) {
     fprintf (stderr, "NCP listen error.\n");
@@ -181,10 +186,14 @@ static void ncp_to_tcp (int sock, const char *host, const char *port)
   fprintf (stderr, "Connection from host %03o on socket %d.\n", ncp_host, sock);
 
   fd = inet_connect (host, port);
+  fprintf (stderr, "Forwarding to host %s port %s.\n", host, port);
   transport (fd, connection);
 
-  if (ncp_close (connection) == -1) {
+  if (ncp_close (connection) == -1)
     fprintf (stderr, "NCP close error.\n");
+
+  if (ncp_unlisten (sock) == -1) {
+    fprintf (stderr, "NCP unlisten error.\n");
     exit (1);
   }
 }
diff --git a/apps/telnet.c b/apps/telnet.c
index 7f3fad8..b2fc216 100644
--- a/apps/telnet.c
+++ b/apps/telnet.c
@@ -400,6 +400,7 @@ static void telnet_server (int host, int sock,
     fprintf (stderr, "NCP listen error.\n");
     exit (1);
   }
+  fprintf (stderr, "Connection from host %03o.\n", host);
 
   reader_fd = reader (connection);
   writer_fd = writer (connection);
@@ -456,8 +457,11 @@ static void telnet_server (int host, int sock,
   kill (reader_pid, SIGTERM);
   kill (writer_pid, SIGTERM);
 
-  if (ncp_close (connection) == -1) {
+  if (ncp_close (connection) == -1)
     fprintf (stderr, "NCP close error.\n");
+
+  if (ncp_unlisten (sock) == -1) {
+    fprintf (stderr, "NCP unlisten error.\n");
     exit (1);
   }
 }
diff --git a/src/libncp.c b/src/libncp.c
index a3cdca1..68c3fb5 100644
--- a/src/libncp.c
+++ b/src/libncp.c
@@ -208,3 +208,20 @@ int ncp_close (int connection)
     return -1;
   return 0;
 }
+
+int ncp_unlisten (unsigned socket)
+{
+  type (WIRE_UNLISTEN);
+  add (socket >> 24);
+  add (socket >> 16);
+  add (socket >> 8);
+  add (socket);
+  if (transact () == -1)
+    return -1;
+  if (u32 (message + 1) != socket)
+    return -1;
+  if (message[5] == 0)
+    return 0;
+  else
+    return -1;
+}
diff --git a/src/ncp.c b/src/ncp.c
index d13c6d0..7851ca9 100644
--- a/src/ncp.c
+++ b/src/ncp.c
@@ -638,6 +638,22 @@ static void reply_close (uint8_t i)
              client.sun_path, strerror (errno));
 }
 
+static void reply_unlisten (uint32_t socket, uint8_t e)
+{
+  uint8_t reply[6];
+  fprintf (stderr, "NCP: Application unlisten reply socket %u: %u\n",
+           socket, e);
+  reply[0] = WIRE_UNLISTEN+1;
+  reply[1] = socket >> 24;
+  reply[2] = socket >> 16;
+  reply[3] = socket >> 8;
+  reply[4] = socket;
+  reply[5] = e;
+  if (sendto (fd, reply, sizeof reply, 0, (struct sockaddr *)&client, len) == -1)
+    fprintf (stderr, "NCP: sendto %s error: %s.\n",
+             client.sun_path, strerror (errno));
+}
+
 static void maybe_reply (int i)
 {
   if ((connection[i].flags & CONN_GOT_BOTH) == CONN_GOT_BOTH) {
@@ -1697,6 +1713,22 @@ static void app_close (void)
   unless_cls (i, cls_timeout);
 }
 
+static void app_unlisten (void)
+{
+  uint32_t socket;
+  int i;
+
+  socket = app[1] << 24 | app[2] << 16 | app[3] << 8 | app[4];
+  fprintf (stderr, "NCP: Application unlisten to socket %u\n", socket);
+  if ((i = find_listen (socket)) != -1) {
+    listening[i].sock = 0;
+    reply_unlisten (socket, 0);
+  } else {
+    fprintf (stderr, "NCP: Not listening to %u.\n", socket);
+    reply_unlisten (socket, 1);
+  }
+}
+
 static void application (void)
 {
   ssize_t n;
@@ -1724,6 +1756,7 @@ static void application (void)
   case WIRE_WRITE:      app_write (n - 2); break;
   case WIRE_INTERRUPT:  app_interrupt (); break;
   case WIRE_CLOSE:      app_close (); break;
+  case WIRE_UNLISTEN:   app_unlisten (); break;
   default:              fprintf (stderr, "NCP: bad application request.\n"); break;
   }
 }
diff --git a/src/ncp.h b/src/ncp.h
index 7027eb4..c4775c9 100644
--- a/src/ncp.h
+++ b/src/ncp.h
@@ -8,3 +8,4 @@ extern int ncp_read (int connection, void *data, int *length);
 extern int ncp_write (int connection, void *data, int *length);
 extern int ncp_interrupt (int connection);
 extern int ncp_close (int connection);
+extern int ncp_unlisten (unsigned socket);
diff --git a/src/wire.h b/src/wire.h
index 45c526f..5109c3b 100644
--- a/src/wire.h
+++ b/src/wire.h
@@ -7,6 +7,7 @@
 #define WIRE_WRITE       9
 #define WIRE_INTERRUPT  11
 #define WIRE_CLOSE      13
+#define WIRE_UNLISTEN   15
 
 static int wire_check (int type, int size)
 {
@@ -25,6 +26,8 @@ static int wire_check (int type, int size)
   case WIRE_INTERRUPT+1: return size == 2;
   case WIRE_CLOSE:       return size == 2;
   case WIRE_CLOSE+1:     return size == 2;
+  case WIRE_UNLISTEN:    return size == 5;
+  case WIRE_UNLISTEN+1:  return size == 6;
   default:               return 0;
   }
 }