diff --git a/src/gateway/session-utils.test.ts b/src/gateway/session-utils.test.ts
index c0afb09a059..ac48d42f07a 100644
--- a/src/gateway/session-utils.test.ts
+++ b/src/gateway/session-utils.test.ts
@@ -1366,6 +1366,95 @@ describe("listSessionsFromStore subagent metadata", () => {
     expect(newParent?.childSessions).toEqual(["agent:main:subagent:shared-child"]);
   });
 
+  test("does not reattach moved children through stale spawnedBy store metadata", () => {
+    const now = Date.now();
+    const store: Record<string, SessionEntry> = {
+      "agent:main:main": {
+        sessionId: "sess-main",
+        updatedAt: now,
+      } as SessionEntry,
+      "agent:main:subagent:old-parent-store": {
+        sessionId: "sess-old-parent-store",
+        updatedAt: now - 4_000,
+        spawnedBy: "agent:main:main",
+      } as SessionEntry,
+      "agent:main:subagent:new-parent-store": {
+        sessionId: "sess-new-parent-store",
+        updatedAt: now - 3_000,
+        spawnedBy: "agent:main:main",
+      } as SessionEntry,
+      "agent:main:subagent:shared-child-store": {
+        sessionId: "sess-shared-child-store",
+        updatedAt: now - 1_000,
+        spawnedBy: "agent:main:subagent:old-parent-store",
+      } as SessionEntry,
+    };
+
+    addSubagentRunForTests({
+      runId: "run-old-parent-store",
+      childSessionKey: "agent:main:subagent:old-parent-store",
+      controllerSessionKey: "agent:main:main",
+      requesterSessionKey: "agent:main:main",
+      requesterDisplayKey: "main",
+      task: "old parent store task",
+      cleanup: "keep",
+      createdAt: now - 10_000,
+      startedAt: now - 9_000,
+    });
+    addSubagentRunForTests({
+      runId: "run-new-parent-store",
+      childSessionKey: "agent:main:subagent:new-parent-store",
+      controllerSessionKey: "agent:main:main",
+      requesterSessionKey: "agent:main:main",
+      requesterDisplayKey: "main",
+      task: "new parent store task",
+      cleanup: "keep",
+      createdAt: now - 8_000,
+      startedAt: now - 7_000,
+    });
+    addSubagentRunForTests({
+      runId: "run-child-store-stale-parent",
+      childSessionKey: "agent:main:subagent:shared-child-store",
+      controllerSessionKey: "agent:main:subagent:old-parent-store",
+      requesterSessionKey: "agent:main:subagent:old-parent-store",
+      requesterDisplayKey: "old-parent-store",
+      task: "shared child stale store parent",
+      cleanup: "keep",
+      createdAt: now - 6_000,
+      startedAt: now - 5_500,
+      endedAt: now - 4_500,
+      outcome: { status: "ok" },
+    });
+    addSubagentRunForTests({
+      runId: "run-child-store-current-parent",
+      childSessionKey: "agent:main:subagent:shared-child-store",
+      controllerSessionKey: "agent:main:subagent:new-parent-store",
+      requesterSessionKey: "agent:main:subagent:new-parent-store",
+      requesterDisplayKey: "new-parent-store",
+      task: "shared child current store parent",
+      cleanup: "keep",
+      createdAt: now - 2_000,
+      startedAt: now - 1_500,
+    });
+
+    const result = listSessionsFromStore({
+      cfg,
+      storePath: "/tmp/sessions.json",
+      store,
+      opts: {},
+    });
+
+    const oldParent = result.sessions.find(
+      (session) => session.key === "agent:main:subagent:old-parent-store",
+    );
+    const newParent = result.sessions.find(
+      (session) => session.key === "agent:main:subagent:new-parent-store",
+    );
+
+    expect(oldParent?.childSessions).toBeUndefined();
+    expect(newParent?.childSessions).toEqual(["agent:main:subagent:shared-child-store"]);
+  });
+
   test("preserves original session timing across follow-up replacement runs", () => {
     const now = Date.now();
     const store: Record<string, SessionEntry> = {
diff --git a/src/gateway/session-utils.ts b/src/gateway/session-utils.ts
index 65ff4a868b4..a6d1e8f41c5 100644
--- a/src/gateway/session-utils.ts
+++ b/src/gateway/session-utils.ts
@@ -277,9 +277,18 @@ function resolveChildSessionKeys(
     }
     const spawnedBy = entry.spawnedBy?.trim();
     const parentSessionKey = entry.parentSessionKey?.trim();
-    if (spawnedBy === controllerSessionKey || parentSessionKey === controllerSessionKey) {
-      childSessionKeys.add(key);
+    if (spawnedBy !== controllerSessionKey && parentSessionKey !== controllerSessionKey) {
+      continue;
     }
+    const latest = getLatestSubagentRunByChildSessionKey(key);
+    if (latest) {
+      const latestControllerSessionKey =
+        latest.controllerSessionKey?.trim() || latest.requesterSessionKey?.trim();
+      if (latestControllerSessionKey !== controllerSessionKey) {
+        continue;
+      }
+    }
+    childSessionKeys.add(key);
   }
   const childSessions = Array.from(childSessionKeys);
   return childSessions.length > 0 ? childSessions : undefined;