diff --git a/include/vulkan/vulkan.h b/include/vulkan/vulkan.h
index fa9f6085d75..d5d699d559b 100644
--- a/include/vulkan/vulkan.h
+++ b/include/vulkan/vulkan.h
@@ -1554,12 +1554,14 @@ typedef struct {
 
 typedef struct {
     uint32_t                                    constantId;
+    size_t                                      size;
     uint32_t                                    offset;
 } VkSpecializationMapEntry;
 
 typedef struct {
     uint32_t                                    mapEntryCount;
     const VkSpecializationMapEntry*             pMap;
+    const size_t                                dataSize;
     const void*                                 pData;
 } VkSpecializationInfo;