diff --git a/extensions/minimax/speech-provider.test.ts b/extensions/minimax/speech-provider.test.ts
index e8ea8969138..42ecba258ca 100644
--- a/extensions/minimax/speech-provider.test.ts
+++ b/extensions/minimax/speech-provider.test.ts
@@ -349,7 +349,10 @@ describe("buildMinimaxSpeechProvider", () => {
       expect(mockFetch).toHaveBeenCalledOnce();
       const [url, init] = mockFetch.mock.calls[0];
       expect(url).toBe("https://api.minimaxi.com/v1/t2a_v2");
-      const body = JSON.parse(init!.body as string);
+      if (!init?.body) {
+        throw new Error("Expected MiniMax TTS fetch init body");
+      }
+      const body = JSON.parse(init.body as string);
       expect(body.model).toBe("speech-2.8-hd");
       expect(body.text).toBe("Hello world");
       expect(body.voice_setting.voice_id).toBe("English_expressive_narrator");
@@ -505,7 +508,11 @@ describe("buildMinimaxSpeechProvider", () => {
 
   describe("listVoices", () => {
     it("returns known voices", async () => {
-      const voices = await provider.listVoices!({} as never);
+      const listVoices = provider.listVoices;
+      if (!listVoices) {
+        throw new Error("Expected MiniMax provider listVoices");
+      }
+      const voices = await listVoices({} as never);
       expect(voices.length).toBeGreaterThan(0);
       expect(voices[0].id).toBe("English_expressive_narrator");
     });
diff --git a/extensions/searxng/src/searxng-search-provider.test.ts b/extensions/searxng/src/searxng-search-provider.test.ts
index 20db0fdf142..8675f50e026 100644
--- a/extensions/searxng/src/searxng-search-provider.test.ts
+++ b/extensions/searxng/src/searxng-search-provider.test.ts
@@ -155,8 +155,12 @@ describe("searxng web search provider", () => {
   it("persists base URL to plugin config via setConfiguredCredentialValue", () => {
     const provider = createSearxngWebSearchProvider();
     const config = {} as Record<string, unknown>;
+    const setConfiguredCredentialValue = provider.setConfiguredCredentialValue;
+    if (!setConfiguredCredentialValue) {
+      throw new Error("Expected SearXNG provider setConfiguredCredentialValue");
+    }
 
-    provider.setConfiguredCredentialValue!(config, "http://search.local:9000");
+    setConfiguredCredentialValue(config, "http://search.local:9000");
 
     expect(
       (
diff --git a/extensions/volcengine/tts.test.ts b/extensions/volcengine/tts.test.ts
index 9af0ad8cae7..34ea952b6a5 100644
--- a/extensions/volcengine/tts.test.ts
+++ b/extensions/volcengine/tts.test.ts
@@ -108,7 +108,11 @@ describe("Volcengine speech provider", () => {
   });
 
   it("lists voices with locale and gender", async () => {
-    const voices = await provider.listVoices!({});
+    const listVoices = provider.listVoices;
+    if (!listVoices) {
+      throw new Error("Expected Volcengine provider listVoices");
+    }
+    const voices = await listVoices({});
     expect(voices.length).toBeGreaterThan(0);
     expect(voices[0]).toMatchObject({ locale: "en-US" });
     expect(voices[0].gender).toMatch(/^(female|male)$/u);