diff --git a/vulkan/libvulkan/swapchain.h b/vulkan/libvulkan/swapchain.h
index 2c60c49..8aac427 100644
--- a/vulkan/libvulkan/swapchain.h
+++ b/vulkan/libvulkan/swapchain.h
@@ -34,6 +34,8 @@
 VKAPI_ATTR VkResult GetSwapchainImagesKHR(VkDevice device, VkSwapchainKHR swapchain_handle, uint32_t* count, VkImage* images);
 VKAPI_ATTR VkResult AcquireNextImageKHR(VkDevice device, VkSwapchainKHR swapchain_handle, uint64_t timeout, VkSemaphore semaphore, VkFence fence, uint32_t* image_index);
 VKAPI_ATTR VkResult QueuePresentKHR(VkQueue queue, const VkPresentInfoKHR* present_info);
+VKAPI_ATTR VkResult GetRefreshCycleDurationGOOGLE(VkDevice device, VkSwapchainKHR swapchain, VkRefreshCycleDurationGOOGLE* pDisplayTimingProperties);
+VKAPI_ATTR VkResult GetPastPresentationTimingGOOGLE(VkDevice device, VkSwapchainKHR swapchain, uint32_t* pPresentationTimingCount, VkPastPresentationTimingGOOGLE* pPresentationTimings);
 // clang-format on
 
 }  // namespace driver