diff --git a/VulkanHppGenerator.cpp b/VulkanHppGenerator.cpp
index 613fd2b..2419b52 100644
--- a/VulkanHppGenerator.cpp
+++ b/VulkanHppGenerator.cpp
@@ -4629,7 +4629,7 @@ int main( int argc, char **argv )
         , m_dispatch( nullptr )
       {}
 
-      ObjectDestroy( Optional<const AllocationCallbacks> allocationCallbacks = nullptr, Dispatch const &dispatch = VULKAN_HPP_DEFAULT_DISPATCHER ) VULKAN_HPP_NOEXCEPT
+      ObjectDestroy( Optional<const AllocationCallbacks> allocationCallbacks, Dispatch const &dispatch = VULKAN_HPP_DEFAULT_DISPATCHER ) VULKAN_HPP_NOEXCEPT
         : m_allocationCallbacks( allocationCallbacks )
         , m_dispatch( &dispatch )
       {}
diff --git a/vulkan/vulkan.hpp b/vulkan/vulkan.hpp
index faaf552..dbfd942 100644
--- a/vulkan/vulkan.hpp
+++ b/vulkan/vulkan.hpp
@@ -2691,7 +2691,7 @@ namespace VULKAN_HPP_NAMESPACE
         , m_dispatch( nullptr )
       {}
 
-      ObjectDestroy( Optional<const AllocationCallbacks> allocationCallbacks = nullptr, Dispatch const &dispatch = VULKAN_HPP_DEFAULT_DISPATCHER ) VULKAN_HPP_NOEXCEPT
+      ObjectDestroy( Optional<const AllocationCallbacks> allocationCallbacks, Dispatch const &dispatch = VULKAN_HPP_DEFAULT_DISPATCHER ) VULKAN_HPP_NOEXCEPT
         : m_allocationCallbacks( allocationCallbacks )
         , m_dispatch( &dispatch )
       {}