diff --git a/gin/v8_initializer.h b/gin/v8_initializer.h
index 74e25c98..1341b77 100644
--- a/gin/v8_initializer.h
+++ b/gin/v8_initializer.h
@@ -30,8 +30,9 @@
  public:
   // This should be called by IsolateHolder::Initialize().
   static void Initialize(IsolateHolder::ScriptMode mode,
-                         const std::string& js_command_line_flags = {},
-                         v8::OOMErrorCallback oom_error_callback = nullptr);
+                         const std::string& js_command_line_flags,
+                         bool disallow_v8_feature_flag_overrides,
+                         v8::OOMErrorCallback oom_error_callback);
 
   // Get address and size information for currently loaded snapshot.
   // If no snapshot is loaded, the return values are null for addresses