diff --git a/src/run.ts b/src/run.ts
index b5fbcc6..666cd78 100644
--- a/src/run.ts
+++ b/src/run.ts
@@ -29,23 +29,22 @@ type RunOptions = {
 }
 
 function killTree(pid: number): void {
-  // Find any processes that escaped the process group (e.g. via setsid)
-  // using a single cross-platform ps call, then kill them before the group.
+  // Find any processes that escaped the process group (e.g. via setsid).
+  // This assumes pid === pgid, which holds because the child is spawned
+  // with detached: true (making it a process group leader).
   try {
     const result = Bun.spawnSync(["ps", "-eo", "pid,pgid"])
     const output = result.stdout.toString()
     const pgid = String(pid)
-    const escapees: number[] = []
     for (const line of output.split("\n")) {
       const parts = line.trim().split(/\s+/)
       if (parts[1] === pgid) {
         const p = parseInt(parts[0]!, 10)
-        if (!isNaN(p) && p !== pid) escapees.push(p)
+        if (!isNaN(p) && p !== pid && p > 1) {
+          try { process.kill(p, "SIGKILL") } catch {}
+        }
       }
     }
-    for (const p of escapees) {
-      try { process.kill(p, "SIGKILL") } catch {}
-    }
   } catch {}
   // Kill the process group
   try { process.kill(-pid, "SIGKILL") } catch {}