diff --git a/internal/remote/batch_tty_test.go b/internal/remote/batch_tty_test.go
new file mode 100644
index 0000000..a87c27d
--- /dev/null
+++ b/internal/remote/batch_tty_test.go
@@ -0,0 +1,81 @@
+package remote
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"syscall"
+	"testing"
+	"time"
+
+	"github.com/creack/pty"
+)
+
+// a batch ssh run must not reach the terminal: tssh ignores BatchMode and
+// reads host key answers from /dev/tty, stealing keys typed into the picker.
+// the check re-runs this test under a pty it owns, with a fake tssh that
+// reports whether it could open /dev/tty
+func TestBatchSSHHasNoTerminal(t *testing.T) {
+	if os.Getenv("TOBI_TEST_TTY_PROBE") == "1" {
+		_, err := os.Open("/dev/tty")
+		out, _ := sshRun(context.Background(), "host", nil, sshOpts{cmd: "true", batch: true, timeout: "1"})
+		fmt.Printf("helper:%v ssh:%s", err == nil, strings.TrimSpace(out))
+		return
+	}
+	dir := t.TempDir()
+	fake := "#!/bin/sh\n(exec 3</dev/tty) 2>/dev/null && echo tty || echo notty\n"
+	if err := os.WriteFile(filepath.Join(dir, "tssh"), []byte(fake), 0755); err != nil {
+		t.Fatal(err)
+	}
+	master, tty, err := pty.Open()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer master.Close()
+	defer tty.Close()
+	var out bytes.Buffer
+	c := exec.Command(os.Args[0], "-test.run=^TestBatchSSHHasNoTerminal$")
+	c.Env = append(os.Environ(), "TOBI_TEST_TTY_PROBE=1", "PATH="+dir+":/usr/bin:/bin")
+	c.Stdin, c.Stdout, c.Stderr = tty, &out, &out
+	c.SysProcAttr = &syscall.SysProcAttr{Setsid: true, Setctty: true}
+	if err := c.Run(); err != nil {
+		t.Fatalf("%v: %s", err, out.String())
+	}
+	if !strings.Contains(out.String(), "helper:true ssh:notty") {
+		t.Fatalf("want the helper on a terminal and ssh off it, got %q", out.String())
+	}
+}
+
+// a probe that times out takes its ProxyCommand with it: killing only ssh
+// orphaned a tailscale nc per unreachable host
+func TestBatchSSHTimeoutKillsItsChildren(t *testing.T) {
+	dir := t.TempDir()
+	pidFile := filepath.Join(dir, "child.pid")
+	fake := "#!/bin/sh\nsleep 60 &\necho $! > " + pidFile + "\nwait\n"
+	if err := os.WriteFile(filepath.Join(dir, "tssh"), []byte(fake), 0755); err != nil {
+		t.Fatal(err)
+	}
+	t.Setenv("PATH", dir+":/usr/bin:/bin")
+	ctx, cancel := context.WithTimeout(context.Background(), 300*time.Millisecond)
+	defer cancel()
+	if _, err := sshRun(ctx, "host", nil, sshOpts{cmd: "true", batch: true, timeout: "1"}); !errors.Is(err, ErrUnreachable) {
+		t.Fatalf("a timed out run should be unreachable, got %v", err)
+	}
+	data, err := os.ReadFile(pidFile)
+	if err != nil {
+		t.Fatal(err)
+	}
+	pid, _ := strconv.Atoi(strings.TrimSpace(string(data)))
+	for deadline := time.Now().Add(time.Second); syscall.Kill(pid, 0) == nil; time.Sleep(10 * time.Millisecond) {
+		if time.Now().After(deadline) {
+			_ = syscall.Kill(pid, syscall.SIGKILL)
+			t.Fatalf("the fake ssh's child %d outlived the timeout", pid)
+		}
+	}
+}
diff --git a/internal/remote/remote.go b/internal/remote/remote.go
index 25e1b55..d46e312 100644
--- a/internal/remote/remote.go
+++ b/internal/remote/remote.go
@@ -18,6 +18,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"syscall"
 	"time"
 
 	"github.com/klauspost/compress/zstd"
@@ -203,6 +204,14 @@ func sshCommand(ctx context.Context, dest string, opts sshOpts) *exec.Cmd {
 	}
 	c := exec.CommandContext(ctx, bin, append(args, dest, opts.cmd)...)
 	c.WaitDelay = 500 * time.Millisecond
+	if opts.batch {
+		// no controlling terminal: tssh ignores BatchMode and prompts for
+		// unknown host keys on /dev/tty, eating the picker's keystrokes.
+		// the new session is also a process group, so a timeout takes the
+		// ProxyCommand down with ssh instead of orphaning it
+		c.SysProcAttr = &syscall.SysProcAttr{Setsid: true}
+		c.Cancel = func() error { return syscall.Kill(-c.Process.Pid, syscall.SIGKILL) }
+	}
 	return c
 }