diff --git a/ssh.c b/ssh.c
index 2b7b2bcba..ec3ce1208 100644
--- a/ssh.c
+++ b/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.644 2026/10/30 06:47:17 djm Exp $ */
+/* $OpenBSD: ssh.c,v 1.645 2026/10/30 08:17:19 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -2512,7 +2512,10 @@ main_sigchld_handler(int sig)
 	int status;
 
 	while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
-	    (pid == -1 && errno == EINTR))
-		;
+	    (pid == -1 && errno == EINTR)) {
+		/* Once reaped, the ProxyCommand's pid may be reused. */
+		if (pid > 0)
+			ssh_proxy_command_reaped(pid);
+	}
 	errno = save_errno;
 }
diff --git a/sshconnect.c b/sshconnect.c
index de1f89b45..8c7ff4494 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.c,v 1.390 2026/10/30 07:44:23 djm Exp $ */
+/* $OpenBSD: sshconnect.c,v 1.391 2026/10/30 08:17:19 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -60,7 +60,7 @@ struct sshkey *previous_host_key = NULL;
 
 static int matching_host_key_dns = 0;
 
-static pid_t proxy_command_pid = 0;
+static volatile pid_t proxy_command_pid = 0;
 
 /* import */
 extern int debug_flag;
@@ -301,15 +301,33 @@ ssh_proxy_connect(struct ssh *ssh, const char *host, const char *host_arg,
 	return 0;
 }
 
+/*
+ * Called from the SIGCHLD handler for each child it reaps. Forget the
+ * proxy command once it has been reaped, as its pid may be reused.
+ */
+void
+ssh_proxy_command_reaped(pid_t pid)
+{
+	if (pid == proxy_command_pid)
+		proxy_command_pid = 0;
+}
+
 void
 ssh_kill_proxy_command(void)
 {
+	sigset_t nset, oset;
+
 	/*
 	 * Send SIGHUP to proxy command if used. We don't wait() in
-	 * case it hangs and instead rely on init to reap the child
+	 * case it hangs and instead rely on init to reap the child.
+	 * Block SIGCHLD so it can't be reaped between the check and kill().
 	 */
+	sigemptyset(&nset);
+	sigaddset(&nset, SIGCHLD);
+	sigprocmask(SIG_BLOCK, &nset, &oset);
 	if (proxy_command_pid > 1)
 		kill(proxy_command_pid, SIGHUP);
+	sigprocmask(SIG_SETMASK, &oset, NULL);
 }
 
 #ifdef HAVE_IFADDRS_H
diff --git a/sshconnect.h b/sshconnect.h
index aad13c20c..41f711311 100644
--- a/sshconnect.h
+++ b/sshconnect.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.h,v 1.52 2026/08/03 06:47:24 djm Exp $ */
+/* $OpenBSD: sshconnect.h,v 1.53 2026/10/30 08:17:19 djm Exp $ */
 
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
@@ -74,6 +74,7 @@ int	 ssh_connect(struct ssh *, const char *, const char *,
 	    struct addrinfo *, struct sockaddr_storage *, u_short,
 	    int, int *, int);
 void	 ssh_kill_proxy_command(void);
+void	 ssh_proxy_command_reaped(pid_t);
 
 void	 ssh_login(struct ssh *, Sensitive *, const char *,
     struct sockaddr_storage *, u_short, struct passwd *, int,