diff --git a/src/resources/extensions/sf/auto.js b/src/resources/extensions/sf/auto.js
index 63f7600c7..f08f30347 100644
--- a/src/resources/extensions/sf/auto.js
+++ b/src/resources/extensions/sf/auto.js
@@ -1547,11 +1547,28 @@ export async function startAuto(ctx, pi, base, verboseMode, options) {
 		interruptedAssessment ?? (await assessInterruptedSession(base));
 	if (freshStartAssessment.classification === "running") {
 		const pid = freshStartAssessment.lock?.pid;
+		// #wiggums: verify PID liveness before reporting. A crashed prior
+		// session leaves a stale lock; telling the operator to kill a dead
+		// PID is misleading. If dead, label as stale + let session-lock
+		// auto-recover on the next acquisition attempt.
+		const pidAlive =
+			pid && Number.isInteger(pid) && pid > 0 && pid !== process.pid
+				? (() => {
+						try {
+							process.kill(pid, 0);
+							return true;
+						} catch (err) {
+							return err?.code === "EPERM";
+						}
+					})()
+				: false;
 		ctx.ui.notify(
-			pid
-				? `Another autonomous mode session (PID ${pid}) appears to be running.\nStop it with \`kill ${pid}\` before starting a new session.`
-				: "Another autonomous mode session appears to be running.",
-			"error",
+			pid && !pidAlive
+				? `Stale autonomous mode lock from dead PID ${pid} — will be auto-recovered on next session-lock acquisition.`
+				: pid
+					? `Another autonomous mode session (PID ${pid}) appears to be running.\nStop it with \`kill ${pid}\` before starting a new session.`
+					: "Another autonomous mode session appears to be running.",
+			pid && !pidAlive ? "warning" : "error",
 			{
 				noticeKind: NOTICE_KIND.BLOCKING_NOTICE,
 				dedupe_key: "auto-start-concurrent-session-blocked",
diff --git a/src/resources/extensions/sf/interrupted-session.js b/src/resources/extensions/sf/interrupted-session.js
index 27f33d438..58bf00771 100644
--- a/src/resources/extensions/sf/interrupted-session.js
+++ b/src/resources/extensions/sf/interrupted-session.js
@@ -164,8 +164,28 @@ export function formatInterruptedSessionSummary(assessment) {
 	}
 	return ["Paused autonomous mode session detected."];
 }
+// #wiggums: verify the PID is actually alive before telling the operator
+// to kill it. Without this check, a crashed prior session leaves the lock
+// pid behind and we tell the operator "kill <dead-PID>" which is
+// confusing + makes the operator think SF is buggy. If the PID isn't
+// alive, label the lock as stale rather than reporting a live session.
+function isPidAlive(pid) {
+	if (!Number.isInteger(pid) || pid <= 0) return false;
+	if (pid === process.pid) return false;
+	try {
+		process.kill(pid, 0);
+		return true;
+	} catch (err) {
+		if (err?.code === "EPERM") return true;
+		return false;
+	}
+}
+
 export function formatInterruptedSessionRunningMessage(assessment) {
 	const pid = assessment.lock?.pid;
+	if (pid && !isPidAlive(pid)) {
+		return `Stale autonomous mode lock from dead PID ${pid}. The previous session crashed without releasing the lock — it will be auto-recovered on the next session-lock acquisition (#sf-stale-lock-auto-recover).`;
+	}
 	return pid
 		? `Another autonomous mode session (PID ${pid}) appears to be running.\nStop it with \`kill ${pid}\` before starting a new session.`
 		: "Another autonomous mode session appears to be running.";