diff --git a/extensions/google/speech-provider.test.ts b/extensions/google/speech-provider.test.ts
index 7a4fc914cd7..8f40f4a3d7f 100644
--- a/extensions/google/speech-provider.test.ts
+++ b/extensions/google/speech-provider.test.ts
@@ -66,6 +66,25 @@ function expectRecordFields(value: unknown, expected: Record<string, unknown>) {
   return actual;
 }
 
+function requireFirstMockArg(mock: ReturnType<typeof vi.fn>, label: string): unknown {
+  const [call] = mock.mock.calls;
+  if (!call) {
+    throw new Error(`Expected ${label}`);
+  }
+  return call[0];
+}
+
+function requireFirstRecordArg(
+  mock: ReturnType<typeof vi.fn>,
+  label: string,
+): Record<string, unknown> {
+  const value = requireFirstMockArg(mock, label);
+  if (!value || typeof value !== "object" || Array.isArray(value)) {
+    throw new Error(`Expected ${label}`);
+  }
+  return value as Record<string, unknown>;
+}
+
 describe("Google speech provider", () => {
   afterEach(() => {
     vi.unstubAllGlobals();
@@ -94,7 +113,7 @@ describe("Google speech provider", () => {
       timeoutMs: 12_345,
     });
 
-    const request = expectRecordFields(requestMock.mock.calls[0]?.[0], {
+    const request = expectRecordFields(requireFirstRecordArg(requestMock, "Google TTS request"), {
       url: "https://generativelanguage.googleapis.com/v1beta/models/gemini-3.1-flash-tts-preview:generateContent",
       body: {
         contents: [
@@ -150,11 +169,14 @@ describe("Google speech provider", () => {
       fileExtension: ".opus",
       voiceCompatible: true,
     });
-    const transcodeArg = expectRecordFields(transcodeAudioBufferToOpusMock.mock.calls[0]?.[0], {
-      inputExtension: "wav",
-      tempPrefix: "tts-google-",
-      timeoutMs: 12_000,
-    });
+    const transcodeArg = expectRecordFields(
+      requireFirstRecordArg(transcodeAudioBufferToOpusMock, "Google TTS transcode request"),
+      {
+        inputExtension: "wav",
+        tempPrefix: "tts-google-",
+        timeoutMs: 12_000,
+      },
+    );
     expect(Buffer.isBuffer(transcodeArg.audioBuffer)).toBe(true);
     const audioBuffer = transcodeArg.audioBuffer as Buffer;
     expect(audioBuffer.subarray(0, 4).toString("ascii")).toBe("RIFF");
@@ -362,10 +384,9 @@ describe("Google speech provider", () => {
       timeoutMs: 10_000,
     });
 
-    expectRecordFields(requestMock.mock.calls[0]?.[0], {
+    const request = expectRecordFields(requireFirstRecordArg(requestMock, "Google TTS request"), {
       url: "https://generativelanguage.googleapis.com/v1beta/models/gemini-3.1-flash-tts-preview:generateContent",
-    });
-    const request = requestMock.mock.calls[0]?.[0] as { headers?: HeadersInit };
+    }) as { headers?: HeadersInit };
     expect(new Headers(request.headers).get("x-goog-api-key")).toBe("env-google-key");
   });
 
@@ -394,7 +415,9 @@ describe("Google speech provider", () => {
       timeoutMs: 10_000,
     });
 
-    const request = requestMock.mock.calls[0]?.[0] as { headers?: HeadersInit };
+    const request = requireFirstRecordArg(requestMock, "Google TTS request") as {
+      headers?: HeadersInit;
+    };
     expect(new Headers(request.headers).get("x-goog-api-key")).toBe("model-provider-google-key");
   });
 
@@ -422,9 +445,12 @@ describe("Google speech provider", () => {
       timeoutMs: 5_000,
     });
 
-    const request = expectRecordFields(postJsonRequestMock.mock.calls[0]?.[0], {
-      url: "https://generativelanguage.googleapis.com/v1beta/models/gemini-3.1-pro-tts:generateContent",
-    });
+    const request = expectRecordFields(
+      requireFirstRecordArg(postJsonRequestMock, "Google telephony TTS request"),
+      {
+        url: "https://generativelanguage.googleapis.com/v1beta/models/gemini-3.1-pro-tts:generateContent",
+      },
+    );
     const body = request.body as {
       contents?: unknown;
       generationConfig?: { speechConfig?: unknown };
@@ -465,7 +491,7 @@ describe("Google speech provider", () => {
       timeoutMs: 10_000,
     });
 
-    const request = requestMock.mock.calls[0]?.[0] as {
+    const request = requireFirstRecordArg(requestMock, "Google TTS request") as {
       body?: { contents?: Array<{ parts?: Array<{ text?: string }> }> };
     };
     expect(request.body?.contents?.[0]?.parts?.[0]?.text).toBe(
@@ -615,7 +641,7 @@ describe("Google speech provider", () => {
     });
 
     const requestConfig = expectRecordFields(
-      resolveProviderHttpRequestConfigMock.mock.calls[0]?.[0],
+      requireFirstRecordArg(resolveProviderHttpRequestConfigMock, "Google TTS HTTP config request"),
       {
         allowPrivateNetwork: true,
       },
@@ -645,7 +671,7 @@ describe("Google speech provider", () => {
     });
 
     const requestConfig = expectRecordFields(
-      resolveProviderHttpRequestConfigMock.mock.calls[0]?.[0],
+      requireFirstRecordArg(resolveProviderHttpRequestConfigMock, "Google TTS HTTP config request"),
       {
         allowPrivateNetwork: true,
       },