diff --git a/ridlbe/c++11/visitors/struct.rb b/ridlbe/c++11/visitors/struct.rb
index 580570ec..1ece1e28 100644
--- a/ridlbe/c++11/visitors/struct.rb
+++ b/ridlbe/c++11/visitors/struct.rb
@@ -59,6 +59,9 @@ def is_array?
 
       def value_initializer
         # When we have an annotation directly applied to this node we are using it
+        if optional?
+          return '{std::nullopt}'
+        end
         unless node.annotations[:default].first.nil?
           "{#{node.annotations[:default].first.fields[:value]}}"
         else