diff --git a/packages/wxt/src/types.ts b/packages/wxt/src/types.ts
index dd9624690..a95c3fff5 100644
--- a/packages/wxt/src/types.ts
+++ b/packages/wxt/src/types.ts
@@ -967,7 +967,7 @@ export interface ExtensionRunnerConfig {
    *   }
    * }
    */
-  chromiumPref?: string;
+  chromiumPref?: Record<string, any>;
   /**
    * By default, chrome opens a random port for debugging. Set this value to use a specific port.
    */