diff --git a/slirp/slirp.c b/slirp/slirp.c
index ab0a8548aa..08c10f2b36 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -495,7 +495,8 @@ void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds)
 				continue;
 
 			      /* else failed */
-			      so->so_state = SS_NOFDREF;
+			      so->so_state &= SS_PERSISTENT_MASK;
+			      so->so_state |= SS_NOFDREF;
 			    }
 			    /* else so->so_state &= ~SS_ISFCONNECTING; */
 
@@ -529,7 +530,8 @@ void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds)
 			      continue; /* Still connecting, continue */
 
 			    /* else failed */
-			    so->so_state = SS_NOFDREF;
+			    so->so_state &= SS_PERSISTENT_MASK;
+			    so->so_state |= SS_NOFDREF;
 
 			    /* tcp_input will take care of it */
 			  } else {
@@ -540,7 +542,8 @@ void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds)
 				  errno == EINPROGRESS || errno == ENOTCONN)
 				continue;
 			      /* else failed */
-			      so->so_state = SS_NOFDREF;
+			      so->so_state &= SS_PERSISTENT_MASK;
+			      so->so_state |= SS_NOFDREF;
 			    } else
 			      so->so_state &= ~SS_ISFCONNECTING;
 
diff --git a/slirp/socket.c b/slirp/socket.c
index 936021e84d..6b3da0a112 100644
--- a/slirp/socket.c
+++ b/slirp/socket.c
@@ -581,7 +581,8 @@ sosendto(struct socket *so, struct mbuf *m)
 	 */
 	if (so->so_expire)
 		so->so_expire = curtime + SO_EXPIRE;
-	so->so_state = SS_ISFCONNECTED; /* So that it gets select()ed */
+	so->so_state &= SS_PERSISTENT_MASK;
+	so->so_state |= SS_ISFCONNECTED; /* So that it gets select()ed */
 	return 0;
 }
 
@@ -620,7 +621,8 @@ tcp_listen(u_int32_t haddr, u_int hport, u_int32_t laddr, u_int lport, int flags
 	if (flags & SS_FACCEPTONCE)
 	   so->so_tcpcb->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT*2;
 
-	so->so_state = (SS_FACCEPTCONN|flags);
+	so->so_state &= SS_PERSISTENT_MASK;
+	so->so_state |= (SS_FACCEPTCONN | flags);
 	so->so_lport = lport; /* Kept in network format */
 	so->so_laddr.s_addr = laddr; /* Ditto */
 
@@ -715,10 +717,12 @@ sofcantrcvmore(struct socket *so)
 		}
 	}
 	so->so_state &= ~(SS_ISFCONNECTING);
-	if (so->so_state & SS_FCANTSENDMORE)
-	   so->so_state = SS_NOFDREF; /* Don't select it */ /* XXX close() here as well? */
-	else
+	if (so->so_state & SS_FCANTSENDMORE) {
+	   so->so_state &= SS_PERSISTENT_MASK;
+	   so->so_state |= SS_NOFDREF; /* Don't select it */
+	} else {
 	   so->so_state |= SS_FCANTRCVMORE;
+	}
 }
 
 static void
@@ -734,10 +738,12 @@ sofcantsendmore(struct socket *so)
             }
 	}
 	so->so_state &= ~(SS_ISFCONNECTING);
-	if (so->so_state & SS_FCANTRCVMORE)
-	   so->so_state = SS_NOFDREF; /* as above */
-	else
+	if (so->so_state & SS_FCANTRCVMORE) {
+	   so->so_state &= SS_PERSISTENT_MASK;
+	   so->so_state |= SS_NOFDREF; /* as above */
+	} else {
 	   so->so_state |= SS_FCANTSENDMORE;
+	}
 }
 
 void
diff --git a/slirp/socket.h b/slirp/socket.h
index ac36aaa4b5..2cf476cb91 100644
--- a/slirp/socket.h
+++ b/slirp/socket.h
@@ -71,6 +71,8 @@ struct socket {
 #define SS_FACCEPTCONN		0x100	/* Socket is accepting connections from a host on the internet */
 #define SS_FACCEPTONCE		0x200	/* If set, the SS_FACCEPTCONN socket will die after one accept */
 
+#define SS_PERSISTENT_MASK	0xf000	/* Unremovable state bits */
+
 extern struct socket tcb;
 
 struct socket * solookup _P((struct socket *, struct in_addr, u_int, struct in_addr, u_int));
diff --git a/slirp/tcp_input.c b/slirp/tcp_input.c
index ab0840d8dd..8789303c8b 100644
--- a/slirp/tcp_input.c
+++ b/slirp/tcp_input.c
@@ -1038,7 +1038,8 @@ trimthenstep6:
 		    soisfconnected(so);
 		    so->so_state &= ~SS_CTL;   /* success XXX */
 		  } else if (ret == 2) {
-		    so->so_state = SS_NOFDREF; /* CTL_CMD */
+		    so->so_state &= SS_PERSISTENT_MASK;
+		    so->so_state |= SS_NOFDREF; /* CTL_CMD */
 		  } else {
 		    needoutput = 1;
 		    tp->t_state = TCPS_FIN_WAIT_1;
diff --git a/slirp/udp.c b/slirp/udp.c
index d675ad3e66..3722845cde 100644
--- a/slirp/udp.c
+++ b/slirp/udp.c
@@ -666,7 +666,8 @@ udp_listen(u_int32_t haddr, u_int hport, u_int32_t laddr, u_int lport,
 	if (flags != SS_FACCEPTONCE)
 	   so->so_expire = 0;
 
-	so->so_state = SS_ISFCONNECTED;
+	so->so_state &= SS_PERSISTENT_MASK;
+	so->so_state |= SS_ISFCONNECTED;
 
 	return so;
 }