diff --git a/extensions/mattermost/src/channel-actions-setup-status.contract.test.ts b/extensions/mattermost/src/channel-actions-setup-status.contract.test.ts
index cb32b3fa034..3ed1863efa9 100644
--- a/extensions/mattermost/src/channel-actions-setup-status.contract.test.ts
+++ b/extensions/mattermost/src/channel-actions-setup-status.contract.test.ts
@@ -70,9 +70,14 @@ describe("mattermost setup contract", () => {
         },
         expectedAccountId: "default",
         assertPatchedConfig: (cfg) => {
-          expect(cfg.channels?.mattermost?.enabled).toBe(true);
-          expect(cfg.channels?.mattermost?.botToken).toBe("test-token");
-          expect(cfg.channels?.mattermost?.baseUrl).toBe("https://chat.example.com");
+          const mattermostConfig = cfg.channels?.mattermost;
+          expect(mattermostConfig).toBeDefined();
+          if (!mattermostConfig) {
+            throw new Error("expected Mattermost config patch");
+          }
+          expect(mattermostConfig.enabled).toBe(true);
+          expect(mattermostConfig.botToken).toBe("test-token");
+          expect(mattermostConfig.baseUrl).toBe("https://chat.example.com");
         },
       },
       {
diff --git a/extensions/mattermost/src/doctor.test.ts b/extensions/mattermost/src/doctor.test.ts
index e5e425d23ad..96ecd7b0357 100644
--- a/extensions/mattermost/src/doctor.test.ts
+++ b/extensions/mattermost/src/doctor.test.ts
@@ -30,16 +30,17 @@ describe("mattermost doctor", () => {
       } as never,
     });
 
-    expect(result.config.channels?.mattermost?.network).toEqual({
+    const mattermostConfig = result.config.channels?.mattermost;
+    expect(mattermostConfig).toBeDefined();
+    if (!mattermostConfig) {
+      throw new Error("expected normalized Mattermost config");
+    }
+    expect(mattermostConfig.network).toEqual({
       dangerouslyAllowPrivateNetwork: true,
     });
-    expect(
-      (
-        result.config.channels?.mattermost?.accounts?.work as
-          | { network?: Record<string, unknown> }
-          | undefined
-      )?.network,
-    ).toEqual({
+    const workAccount = mattermostConfig.accounts?.work as { network?: Record<string, unknown> };
+    expect(workAccount).toBeDefined();
+    expect(workAccount.network).toEqual({
       dangerouslyAllowPrivateNetwork: false,
     });
   });
diff --git a/extensions/mattermost/src/setup.test.ts b/extensions/mattermost/src/setup.test.ts
index 231f6a7be96..361abb6b12d 100644
--- a/extensions/mattermost/src/setup.test.ts
+++ b/extensions/mattermost/src/setup.test.ts
@@ -391,8 +391,13 @@ describe("mattermost setup", () => {
       ([params]) => (params as { message: string }).message,
     );
     expect(textMessages).toEqual(["Enter Mattermost bot token", "Enter Mattermost base URL"]);
-    expect(result.cfg.channels?.mattermost?.botToken).toBe("bot-token");
-    expect(result.cfg.channels?.mattermost?.baseUrl).toBe("https://chat.example.com");
+    const mattermostConfig = result.cfg.channels?.mattermost;
+    expect(mattermostConfig).toBeDefined();
+    if (!mattermostConfig) {
+      throw new Error("expected Mattermost config");
+    }
+    expect(mattermostConfig.botToken).toBe("bot-token");
+    expect(mattermostConfig.baseUrl).toBe("https://chat.example.com");
     expect(result.accountId).toBe(DEFAULT_ACCOUNT_ID);
   });
 });