diff --git a/ssh.c b/ssh.c
index 3af4ba94..c7b724b9 100644
--- a/ssh.c
+++ b/ssh.c
@@ -1982,7 +1982,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
 }
 
 void sshfwd_close(struct ssh_channel *c) {
-    if (c) {
+    if (c && !c->closes) {
         if (ssh_version == 1) {
             send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
         } else {
diff --git a/x11fwd.c b/x11fwd.c
index 8ace77d5..2b4a6bc5 100644
--- a/x11fwd.c
+++ b/x11fwd.c
@@ -189,7 +189,10 @@ char *x11_init (Socket *s, char *display, void *c) {
 }
 
 void x11_close (Socket s) {
-    struct X11Private *pr = (struct X11Private *)sk_get_private_ptr(s);
+    struct X11Private *pr;
+	if (!s)
+		return;
+	pr = (struct X11Private *)sk_get_private_ptr(s);
 
     if (pr->auth_protocol) {
         sfree(pr->auth_protocol);