diff --git a/extensions/thread-ownership/index.test.ts b/extensions/thread-ownership/index.test.ts
index 1db1c51ebe8..41233a742b1 100644
--- a/extensions/thread-ownership/index.test.ts
+++ b/extensions/thread-ownership/index.test.ts
@@ -28,6 +28,17 @@ describe("thread-ownership plugin", () => {
     }),
   };
 
+  function expectOwnershipFetchCall(index: number, url: string, agentId: string) {
+    const call = vi.mocked(globalThis.fetch).mock.calls[index];
+    if (!call) {
+      throw new Error(`expected ownership fetch call ${index}`);
+    }
+    expect(call[0]).toBe(url);
+    const init = call[1];
+    expect(init?.method).toBe("POST");
+    expect(init?.body).toBe(JSON.stringify({ agent_id: agentId }));
+  }
+
   beforeEach(() => {
     vi.clearAllMocks();
     for (const key of Object.keys(hooks)) {
@@ -109,12 +120,10 @@ describe("thread-ownership plugin", () => {
       const result = await sendSlackThreadMessage();
 
       expect(result).toBeUndefined();
-      expect(globalThis.fetch).toHaveBeenCalledWith(
+      expectOwnershipFetchCall(
+        0,
         "http://localhost:8750/api/v1/ownership/C123/1234.5678",
-        expect.objectContaining({
-          method: "POST",
-          body: JSON.stringify({ agent_id: "test-agent" }),
-        }),
+        "test-agent",
       );
     });
 
@@ -133,12 +142,10 @@ describe("thread-ownership plugin", () => {
       );
 
       expect(result).toBeUndefined();
-      expect(globalThis.fetch).toHaveBeenCalledWith(
+      expectOwnershipFetchCall(
+        0,
         "http://localhost:8750/api/v1/ownership/C123/1234.5678",
-        expect.objectContaining({
-          method: "POST",
-          body: JSON.stringify({ agent_id: "test-agent" }),
-        }),
+        "test-agent",
       );
     });
 
@@ -157,12 +164,10 @@ describe("thread-ownership plugin", () => {
       );
 
       expect(result).toBeUndefined();
-      expect(globalThis.fetch).toHaveBeenCalledWith(
+      expectOwnershipFetchCall(
+        0,
         "http://localhost:8750/api/v1/ownership/C123/1234.5678",
-        expect.objectContaining({
-          method: "POST",
-          body: JSON.stringify({ agent_id: "test-agent" }),
-        }),
+        "test-agent",
       );
     });
 
@@ -183,12 +188,10 @@ describe("thread-ownership plugin", () => {
       );
 
       expect(result).toBeUndefined();
-      expect(globalThis.fetch).toHaveBeenCalledWith(
+      expectOwnershipFetchCall(
+        0,
         "http://localhost:8750/api/v1/ownership/C123/1234.5678",
-        expect.objectContaining({
-          method: "POST",
-          body: JSON.stringify({ agent_id: "test-agent" }),
-        }),
+        "test-agent",
       );
     });
 
@@ -238,12 +241,10 @@ describe("thread-ownership plugin", () => {
       );
 
       expect(result).toBeUndefined();
-      expect(globalThis.fetch).toHaveBeenCalledWith(
+      expectOwnershipFetchCall(
+        0,
         "http://localhost:8750/api/v1/ownership/C123/1234.5678",
-        expect.objectContaining({
-          method: "POST",
-          body: JSON.stringify({ agent_id: "test-agent" }),
-        }),
+        "test-agent",
       );
     });
 
@@ -255,7 +256,9 @@ describe("thread-ownership plugin", () => {
       const result = await sendSlackThreadMessage();
 
       expect(result).toEqual({ cancel: true });
-      expect(api.logger.info).toHaveBeenCalledWith(expect.stringContaining("cancelled send"));
+      const infoMessage = vi.mocked(api.logger.info).mock.calls[0]?.[0];
+      expect(typeof infoMessage).toBe("string");
+      expect(infoMessage).toContain("cancelled send");
     });
 
     it("fails open on network error", async () => {
@@ -264,9 +267,9 @@ describe("thread-ownership plugin", () => {
       const result = await sendSlackThreadMessage();
 
       expect(result).toBeUndefined();
-      expect(api.logger.warn).toHaveBeenCalledWith(
-        expect.stringContaining("ownership check failed"),
-      );
+      const warningMessage = vi.mocked(api.logger.warn).mock.calls[0]?.[0];
+      expect(typeof warningMessage).toBe("string");
+      expect(warningMessage).toContain("ownership check failed");
     });
   });
 
@@ -416,12 +419,10 @@ describe("thread-ownership plugin", () => {
         { channelId: "slack", conversationId: "C789" },
       );
 
-      expect(globalThis.fetch).toHaveBeenCalledWith(
+      expectOwnershipFetchCall(
+        0,
         "http://localhost:8750/api/v1/ownership/C789/8888.0005",
-        expect.objectContaining({
-          method: "POST",
-          body: JSON.stringify({ agent_id: "live-agent" }),
-        }),
+        "live-agent",
       );
     });