diff --git a/src/infra/json-files.ts b/src/infra/json-files.ts
index 68e56b38a5e..14084a74f5a 100644
--- a/src/infra/json-files.ts
+++ b/src/infra/json-files.ts
@@ -36,7 +36,7 @@ export async function readJsonFile<T>(filePath: string): Promise<T | null> {
   }
 }
 
-export function readJsonFileSync<T>(filePath: string): T | null {
+export function readJsonFileSync(filePath: string): unknown {
   try {
     const raw = readFileSync(filePath, "utf8");
     return JSON.parse(raw) as T;
diff --git a/src/plugins/installed-plugin-index-store.ts b/src/plugins/installed-plugin-index-store.ts
index 15bf63e76f3..cfdb53d3e36 100644
--- a/src/plugins/installed-plugin-index-store.ts
+++ b/src/plugins/installed-plugin-index-store.ts
@@ -130,7 +130,7 @@ export async function readPersistedInstalledPluginIndex(
 export function readPersistedInstalledPluginIndexSync(
   options: InstalledPluginIndexStoreOptions = {},
 ): InstalledPluginIndex | null {
-  const parsed = readJsonFileSync<unknown>(resolveInstalledPluginIndexStorePath(options));
+  const parsed = readJsonFileSync(resolveInstalledPluginIndexStorePath(options));
   return parseInstalledPluginIndex(parsed);
 }
 
diff --git a/src/plugins/plugin-registry.test.ts b/src/plugins/plugin-registry.test.ts
index 83ec41ec975..884ec38fda4 100644
--- a/src/plugins/plugin-registry.test.ts
+++ b/src/plugins/plugin-registry.test.ts
@@ -200,10 +200,11 @@ describe("plugin registry facade", () => {
 
   it("normalizes plugin config ids through registry contribution aliases", () => {
     const index = createIndex("openai");
+    const plugin = index.plugins[0];
     index.plugins[0] = {
-      ...index.plugins[0]!,
+      ...plugin,
       contributions: {
-        ...index.plugins[0]!.contributions,
+        ...plugin.contributions,
         providers: ["openai", "openai-codex"],
         channels: ["openai-chat"],
       },