diff --git a/ash/src/vk/definitions.rs b/ash/src/vk/definitions.rs
index e95c976cc..646e52ac6 100644
--- a/ash/src/vk/definitions.rs
+++ b/ash/src/vk/definitions.rs
@@ -45232,11 +45232,17 @@ pub struct TransformMatrixKHR {
 }
 #[repr(C)]
 #[derive(Copy, Clone)]
+pub union AccelerationStructureReferenceKHR {
+    pub device_handle: DeviceAddress,
+    pub host_handle: AccelerationStructureKHR,
+}
+#[repr(C)]
+#[derive(Copy, Clone)]
 pub struct AccelerationStructureInstanceKHR {
     pub transform: TransformMatrixKHR,
     pub instance_custom_index_and_mask: u32,
     pub instance_shader_binding_table_record_offset_and_flags: u32,
-    pub acceleration_structure_reference: u64,
+    pub acceleration_structure_reference: AccelerationStructureReferenceKHR,
 }
 #[repr(C)]
 #[derive(Copy, Clone, Debug)]
diff --git a/generator/src/lib.rs b/generator/src/lib.rs
index 022a52b02..ed237f7dd 100644
--- a/generator/src/lib.rs
+++ b/generator/src/lib.rs
@@ -1977,13 +1977,19 @@ pub fn generate_struct(
 
     if &_struct.name == "VkAccelerationStructureInstanceKHR" {
         return quote! {
+            #[repr(C)]
+            #[derive(Copy, Clone)]
+            pub union AccelerationStructureReferenceKHR {
+                pub device_handle: DeviceAddress,
+                pub host_handle: AccelerationStructureKHR,
+            }
             #[repr(C)]
             #[derive(Copy, Clone)]
             pub struct AccelerationStructureInstanceKHR {
                 pub transform: TransformMatrixKHR,
                 pub instance_custom_index_and_mask: u32,
                 pub instance_shader_binding_table_record_offset_and_flags: u32,
-                pub acceleration_structure_reference: u64,
+                pub acceleration_structure_reference: AccelerationStructureReferenceKHR,
             }
         };
     }