diff --git a/packages/integration/src/gerrit/core.test.ts b/packages/integration/src/gerrit/core.test.ts
index 3226c7bf3e..19bddcf518 100644
--- a/packages/integration/src/gerrit/core.test.ts
+++ b/packages/integration/src/gerrit/core.test.ts
@@ -47,6 +47,7 @@ describe('gerrit core', () => {
     };
     const configWithDedicatedGitiles: GerritIntegrationConfig = {
       host: 'gerrit.com',
+      baseUrl: 'https://gerrit.com/gerrit',
       gitilesBaseUrl: 'https://dedicated-gitiles-server.com/gerrit/gitiles',
     };
     it('can create an archive url for a branch', () => {
diff --git a/packages/integration/src/gerrit/core.ts b/packages/integration/src/gerrit/core.ts
index b69aca429d..4b7242730e 100644
--- a/packages/integration/src/gerrit/core.ts
+++ b/packages/integration/src/gerrit/core.ts
@@ -157,10 +157,15 @@ export function getAuthenticationPrefix(
 export function getGitilesAuthenticationUrl(
   config: GerritIntegrationConfig,
 ): string {
-  if (config.gitilesBaseUrl!.startsWith(config.baseUrl!)) {
-    return config.gitilesBaseUrl!.replace(
-      config.baseUrl!.concat('/'),
-      config.baseUrl!.concat(getAuthenticationPrefix(config)),
+  if (!config.baseUrl || !config.gitilesBaseUrl) {
+    throw new Error(
+      'Unexpected Gerrit config values. baseUrl or gitilesBaseUrl not set.',
+    );
+  }
+  if (config.gitilesBaseUrl.startsWith(config.baseUrl)) {
+    return config.gitilesBaseUrl.replace(
+      config.baseUrl.concat('/'),
+      config.baseUrl.concat(getAuthenticationPrefix(config)),
     );
   }
   if (config.password) {