diff --git a/include/private/vulkan_private_extensions.h b/include/private/vulkan_private_extensions.h
new file mode 100644
index 00000000..c148fa21
--- /dev/null
+++ b/include/private/vulkan_private_extensions.h
@@ -0,0 +1,35 @@
+#ifndef __VULKAN_PRIVATE_EXTENSIONS_H__
+#define __VULKAN_PRIVATE_EXTENSIONS_H__
+
+/* Temporary kludge since these types are not public. */
+
+#define VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DESCRIPTOR_SET_HOST_MAPPING_FEATURES_VALVE ((VkStructureType)1000420000)
+#define VK_STRUCTURE_TYPE_DESCRIPTOR_SET_BINDING_REFERENCE_VALVE ((VkStructureType)1000420001)
+#define VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_HOST_MAPPING_INFO_VALVE ((VkStructureType)1000420002)
+
+#define VK_VALVE_DESCRIPTOR_SET_HOST_MAPPING_SPEC_VERSION 1
+#define VK_VALVE_DESCRIPTOR_SET_HOST_MAPPING_EXTENSION_NAME "VK_VALVE_descriptor_set_host_mapping"
+typedef struct VkPhysicalDeviceDescriptorSetHostMappingFeaturesVALVE {
+    VkStructureType    sType;
+    void*              pNext;
+    VkBool32           descriptorSetHostMapping;
+} VkPhysicalDeviceDescriptorSetHostMappingFeaturesVALVE;
+
+typedef struct VkDescriptorSetBindingReferenceVALVE {
+    VkStructureType          sType;
+    const void*              pNext;
+    VkDescriptorSetLayout    descriptorSetLayout;
+    uint32_t                 binding;
+} VkDescriptorSetBindingReferenceVALVE;
+
+typedef struct VkDescriptorSetLayoutHostMappingInfoVALVE {
+    VkStructureType    sType;
+    void*              pNext;
+    size_t             descriptorOffset;
+    uint32_t           descriptorSize;
+} VkDescriptorSetLayoutHostMappingInfoVALVE;
+
+typedef void (VKAPI_PTR *PFN_vkGetDescriptorSetLayoutHostMappingInfoVALVE)(VkDevice device, const VkDescriptorSetBindingReferenceVALVE* pBindingReference, VkDescriptorSetLayoutHostMappingInfoVALVE* pHostMapping);
+typedef void (VKAPI_PTR *PFN_vkGetDescriptorSetHostMappingVALVE)(VkDevice device, VkDescriptorSet descriptorSet, void** ppData);
+
+#endif
diff --git a/include/vkd3d.h b/include/vkd3d.h
index 3b81c509..34845eb6 100644
--- a/include/vkd3d.h
+++ b/include/vkd3d.h
@@ -31,6 +31,7 @@
 #  define VK_USE_PLATFORM_WIN32_KHR
 # endif
 # include <vulkan/vulkan.h>
+# include "private/vulkan_private_extensions.h"
 #endif  /* VKD3D_NO_VULKAN_H */
 
 #define VKD3D_MIN_API_VERSION VK_API_VERSION_1_1
diff --git a/include/vkd3d_win32.h b/include/vkd3d_win32.h
index d9d0128d..9b58fa12 100644
--- a/include/vkd3d_win32.h
+++ b/include/vkd3d_win32.h
@@ -51,6 +51,7 @@
 
 #define VK_USE_PLATFORM_WIN32_KHR
 #include <vulkan/vulkan.h>
+#include "private/vulkan_private_extensions.h"
 
 #ifdef __MINGW32__
 # define static