diff --git a/packages/adapter-utils/src/server-utils.test.ts b/packages/adapter-utils/src/server-utils.test.ts
index e96df8c8b79..4579e1672a7 100644
--- a/packages/adapter-utils/src/server-utils.test.ts
+++ b/packages/adapter-utils/src/server-utils.test.ts
@@ -157,6 +157,35 @@ describe("runChildProcess", () => {
     expect(await waitForPidExit(descendantPid, 2_000)).toBe(true);
   });
 
+  it.skipIf(process.platform === "win32")("cleans up a still-running child after terminal output", async () => {
+    const result = await runChildProcess(
+      randomUUID(),
+      process.execPath,
+      [
+        "-e",
+        [
+          "process.stdout.write(`${JSON.stringify({ type: 'result', result: 'done' })}\\n`);",
+          "setInterval(() => {}, 1000);",
+        ].join(" "),
+      ],
+      {
+        cwd: process.cwd(),
+        env: {},
+        timeoutSec: 0,
+        graceSec: 1,
+        onLog: async () => {},
+        terminalResultCleanup: {
+          graceMs: 100,
+          hasTerminalResult: ({ stdout }) => stdout.includes('"type":"result"'),
+        },
+      },
+    );
+
+    expect(result.timedOut).toBe(false);
+    expect(result.signal).toBe("SIGTERM");
+    expect(result.stdout).toContain('"type":"result"');
+  });
+
   it.skipIf(process.platform === "win32")("does not clean up noisy runs that have no terminal output", async () => {
     const runId = randomUUID();
     let observed = "";
diff --git a/packages/adapter-utils/src/server-utils.ts b/packages/adapter-utils/src/server-utils.ts
index c6fc3ea8ec0..88acc936a9a 100644
--- a/packages/adapter-utils/src/server-utils.ts
+++ b/packages/adapter-utils/src/server-utils.ts
@@ -1345,7 +1345,6 @@ export async function runChildProcess(
         let stdout = "";
         let stderr = "";
         let logChain: Promise<void> = Promise.resolve();
-        let childExited = false;
         let terminalResultSeen = false;
         let terminalCleanupStarted = false;
         let terminalCleanupTimer: NodeJS.Timeout | null = null;
@@ -1379,7 +1378,7 @@ export async function runChildProcess(
               onLogError(err, runId, "failed to inspect terminal adapter output");
             }
           }
-          if (!terminalResultSeen || !childExited) return;
+          if (!terminalResultSeen) return;
 
           if (terminalCleanupTimer) return;
           const graceMs = Math.max(0, terminalCleanup.graceMs ?? 5_000);
@@ -1462,7 +1461,6 @@ export async function runChildProcess(
         });
 
         child.on("exit", () => {
-          childExited = true;
           maybeArmTerminalResultCleanup();
         });