diff --git a/VulkanHppGenerator.cpp b/VulkanHppGenerator.cpp
index a9c9af5..e13eb60 100644
--- a/VulkanHppGenerator.cpp
+++ b/VulkanHppGenerator.cpp
@@ -3255,6 +3255,11 @@ std::string VulkanHppGenerator::constructArgumentListEnhanced( std::vector<Param
             }
 
             argumentList += "ArrayProxy<" + type + "> const & " + name;
+            if ( params[i].optional && !definition )
+            {
+              argumentList += " VULKAN_HPP_DEFAULT_ARGUMENT_NULLPTR_ASSIGNMENT";
+              hasDefaultAssignment = true;
+            }
           }
         }
       }
diff --git a/vulkan/vulkan.hpp b/vulkan/vulkan.hpp
index dd3794d..04db6c6 100644
--- a/vulkan/vulkan.hpp
+++ b/vulkan/vulkan.hpp
@@ -37804,7 +37804,7 @@ namespace VULKAN_HPP_NAMESPACE
     void beginTransformFeedbackEXT( uint32_t                                               firstCounterBuffer,
                                     ArrayProxy<const VULKAN_HPP_NAMESPACE::Buffer> const & counterBuffers,
                                     ArrayProxy<const VULKAN_HPP_NAMESPACE::DeviceSize> const & counterBufferOffsets
-                                                       VULKAN_HPP_DEFAULT_ARGUMENT_ASSIGNMENT,
+                                                       VULKAN_HPP_DEFAULT_ARGUMENT_NULLPTR_ASSIGNMENT,
                                     Dispatch const & d VULKAN_HPP_DEFAULT_DISPATCHER_ASSIGNMENT ) const
       VULKAN_HPP_NOEXCEPT_WHEN_NO_EXCEPTIONS;
 #endif /*VULKAN_HPP_DISABLE_ENHANCED_MODE*/
@@ -37866,7 +37866,7 @@ namespace VULKAN_HPP_NAMESPACE
       uint32_t                                                         firstBinding,
       ArrayProxy<const VULKAN_HPP_NAMESPACE::Buffer> const &           buffers,
       ArrayProxy<const VULKAN_HPP_NAMESPACE::DeviceSize> const &       offsets,
-      ArrayProxy<const VULKAN_HPP_NAMESPACE::DeviceSize> const & sizes VULKAN_HPP_DEFAULT_ARGUMENT_ASSIGNMENT,
+      ArrayProxy<const VULKAN_HPP_NAMESPACE::DeviceSize> const & sizes VULKAN_HPP_DEFAULT_ARGUMENT_NULLPTR_ASSIGNMENT,
       Dispatch const & d VULKAN_HPP_DEFAULT_DISPATCHER_ASSIGNMENT ) const VULKAN_HPP_NOEXCEPT_WHEN_NO_EXCEPTIONS;
 #endif /*VULKAN_HPP_DISABLE_ENHANCED_MODE*/
 
@@ -37899,8 +37899,8 @@ namespace VULKAN_HPP_NAMESPACE
       uint32_t                                                           firstBinding,
       ArrayProxy<const VULKAN_HPP_NAMESPACE::Buffer> const &             buffers,
       ArrayProxy<const VULKAN_HPP_NAMESPACE::DeviceSize> const &         offsets,
-      ArrayProxy<const VULKAN_HPP_NAMESPACE::DeviceSize> const & sizes   VULKAN_HPP_DEFAULT_ARGUMENT_ASSIGNMENT,
-      ArrayProxy<const VULKAN_HPP_NAMESPACE::DeviceSize> const & strides VULKAN_HPP_DEFAULT_ARGUMENT_ASSIGNMENT,
+      ArrayProxy<const VULKAN_HPP_NAMESPACE::DeviceSize> const & sizes   VULKAN_HPP_DEFAULT_ARGUMENT_NULLPTR_ASSIGNMENT,
+      ArrayProxy<const VULKAN_HPP_NAMESPACE::DeviceSize> const & strides VULKAN_HPP_DEFAULT_ARGUMENT_NULLPTR_ASSIGNMENT,
       Dispatch const & d VULKAN_HPP_DEFAULT_DISPATCHER_ASSIGNMENT ) const VULKAN_HPP_NOEXCEPT_WHEN_NO_EXCEPTIONS;
 #endif /*VULKAN_HPP_DISABLE_ENHANCED_MODE*/
 
@@ -38407,7 +38407,7 @@ namespace VULKAN_HPP_NAMESPACE
     void endTransformFeedbackEXT( uint32_t                                               firstCounterBuffer,
                                   ArrayProxy<const VULKAN_HPP_NAMESPACE::Buffer> const & counterBuffers,
                                   ArrayProxy<const VULKAN_HPP_NAMESPACE::DeviceSize> const & counterBufferOffsets
-                                                     VULKAN_HPP_DEFAULT_ARGUMENT_ASSIGNMENT,
+                                                     VULKAN_HPP_DEFAULT_ARGUMENT_NULLPTR_ASSIGNMENT,
                                   Dispatch const & d VULKAN_HPP_DEFAULT_DISPATCHER_ASSIGNMENT ) const
       VULKAN_HPP_NOEXCEPT_WHEN_NO_EXCEPTIONS;
 #endif /*VULKAN_HPP_DISABLE_ENHANCED_MODE*/
@@ -53573,7 +53573,7 @@ namespace VULKAN_HPP_NAMESPACE
                          getAccelerationStructureBuildSizesKHR(
                            VULKAN_HPP_NAMESPACE::AccelerationStructureBuildTypeKHR buildType,
                            const AccelerationStructureBuildGeometryInfoKHR &       buildInfo,
-                           ArrayProxy<const uint32_t> const & maxPrimitiveCounts   VULKAN_HPP_DEFAULT_ARGUMENT_ASSIGNMENT,
+                           ArrayProxy<const uint32_t> const & maxPrimitiveCounts   VULKAN_HPP_DEFAULT_ARGUMENT_NULLPTR_ASSIGNMENT,
                            Dispatch const & d VULKAN_HPP_DEFAULT_DISPATCHER_ASSIGNMENT ) const VULKAN_HPP_NOEXCEPT_WHEN_NO_EXCEPTIONS;
 #endif /*VULKAN_HPP_DISABLE_ENHANCED_MODE*/