diff --git a/cli/src/runner/controlClient.ts b/cli/src/runner/controlClient.ts
index b1d8de3c..fa9daa1d 100644
--- a/cli/src/runner/controlClient.ts
+++ b/cli/src/runner/controlClient.ts
@@ -10,7 +10,7 @@ import packageJson from '../../package.json';
 import { existsSync, statSync } from 'node:fs';
 import { join } from 'node:path';
 import { isBunCompiled, projectPath } from '@/projectPath';
-import { isProcessAlive, killProcess } from '@/utils/process';
+import { isProcessAlive, isHapiRunnerProcess, killProcess } from '@/utils/process';
 import { configuration } from '@/configuration';
 import { hashRunnerCliApiToken, isRunnerStateCompatibleWithIdentity } from './runnerIdentity';
 
@@ -143,12 +143,12 @@ export async function checkIfRunnerRunningAndCleanupStaleState(): Promise<boolea
     return false;
   }
 
-  // Check if the runner is running
-  if (isProcessAlive(state.pid)) {
+  // Verify PID is alive AND belongs to hapi (not a reused PID from another process)
+  if (isHapiRunnerProcess(state.pid)) {
     return true;
   }
 
-  logger.debug('[RUNNER RUN] Runner PID not running, cleaning up state');
+  logger.debug('[RUNNER RUN] Runner PID not running or not a hapi process, cleaning up state');
   await cleanupRunnerState();
   return false;
 }
diff --git a/cli/src/utils/process.ts b/cli/src/utils/process.ts
index e2726bc2..3c82d82c 100644
--- a/cli/src/utils/process.ts
+++ b/cli/src/utils/process.ts
@@ -16,6 +16,32 @@ export function isProcessAlive(pid: number): boolean {
   }
 }
 
+// ponytail: ps -p is cheap and avoids PID-reuse false positives after OS upgrades/reboots
+function isRunnerCommand(commandLine: string): boolean {
+  return /(?:^|\s)runner(?:\s|$)/.test(commandLine) && /(?:^|\s)start-sync(?:\s|$)/.test(commandLine);
+}
+
+export function isHapiRunnerProcess(pid: number): boolean {
+  if (!isProcessAlive(pid)) {
+    return false;
+  }
+  if (isWindows()) {
+    const result = spawn.sync('wmic', ['process', 'where', `ProcessId=${pid}`, 'get', 'CommandLine'], { stdio: 'pipe' });
+    if (result.error) {
+      return true;
+    }
+    if (result.status !== 0) {
+      return isProcessAlive(pid);
+    }
+    return isRunnerCommand(result.stdout?.toString() ?? '');
+  }
+  const result = spawn.sync('ps', ['-p', String(pid), '-o', 'command='], { stdio: 'pipe' });
+  if (result.error || result.status !== 0) {
+    return isProcessAlive(pid);
+  }
+  return isRunnerCommand(result.stdout?.toString() ?? '');
+}
+
 function killProcessWindows(pid: number, force: boolean): boolean {
   if (!isProcessAlive(pid)) {
     return true;