diff --git a/layer/wsi_layer_experimental.hpp b/layer/wsi_layer_experimental.hpp
index bcb751b..d7251a5 100644
--- a/layer/wsi_layer_experimental.hpp
+++ b/layer/wsi_layer_experimental.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2024-2025 Arm Limited.
+ * Copyright (c) 2024-2026 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -34,164 +34,6 @@
 
 #if VULKAN_WSI_LAYER_EXPERIMENTAL
 
-#define VK_EXT_present_timing 1
-#define VK_EXT_PRESENT_TIMING_SPEC_VERSION 1
-#define VK_EXT_PRESENT_TIMING_EXTENSION_NAME "VK_EXT_present_timing"
-#define VK_ERROR_PRESENT_TIMING_QUEUE_FULL_EXT ((VkResult)(-1000208000))
-#define VK_TIME_DOMAIN_PRESENT_STAGE_LOCAL_EXT ((VkTimeDomainEXT)(1000208000))
-#define VK_TIME_DOMAIN_SWAPCHAIN_LOCAL_EXT ((VkTimeDomainEXT)(1000208001))
-#define VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PRESENT_TIMING_FEATURES_EXT ((VkStructureType)1000208000)
-#define VK_STRUCTURE_TYPE_PRESENT_TIMING_SURFACE_CAPABILITIES_EXT ((VkStructureType)1000208008)
-#define VK_STRUCTURE_TYPE_SWAPCHAIN_TIMING_PROPERTIES_EXT ((VkStructureType)1000208001)
-#define VK_STRUCTURE_TYPE_SWAPCHAIN_TIME_DOMAIN_PROPERTIES_EXT ((VkStructureType)1000208002)
-#define VK_STRUCTURE_TYPE_SWAPCHAIN_CALIBRATED_TIMESTAMP_INFO_EXT ((VkStructureType)1000208009)
-#define VK_STRUCTURE_TYPE_PAST_PRESENTATION_TIMING_EXT ((VkStructureType)1000208007)
-#define VK_STRUCTURE_TYPE_PAST_PRESENTATION_TIMING_PROPERTIES_EXT ((VkStructureType)1000208006)
-#define VK_STRUCTURE_TYPE_PAST_PRESENTATION_TIMING_INFO_EXT ((VkStructureType)1000208005)
-#define VK_STRUCTURE_TYPE_PRESENT_TIMING_INFO_EXT ((VkStructureType)1000208004)
-#define VK_STRUCTURE_TYPE_PRESENT_TIMINGS_INFO_EXT ((VkStructureType)1000208003)
-
-/* Placeholder. Need to get the real value. */
-#define VK_SWAPCHAIN_CREATE_PRESENT_TIMING_BIT_EXT ((VkSwapchainCreateFlagsKHR)0x00000200)
-typedef VkFlags VkPresentStageFlagsEXT;
-typedef VkFlags VkPresentTimingInfoFlagsEXT;
-
-typedef struct VkPhysicalDevicePresentTimingFeaturesEXT
-{
-   VkStructureType sType;
-   void *pNext;
-   VkBool32 presentTiming;
-   VkBool32 presentAtAbsoluteTime;
-   VkBool32 presentAtRelativeTime;
-} VkPhysicalDevicePresentTimingFeaturesEXT;
-typedef struct VkPresentTimingSurfaceCapabilitiesEXT
-{
-   VkStructureType sType;
-   void *pNext;
-   VkBool32 presentTimingSupported;
-   VkBool32 presentAtAbsoluteTimeSupported;
-   VkBool32 presentAtRelativeTimeSupported;
-   VkPresentStageFlagsEXT presentStageQueries;
-} VkPresentTimingSurfaceCapabilitiesEXT;
-
-typedef enum VkPresentStageFlagBitsEXT
-{
-   VK_PRESENT_STAGE_QUEUE_OPERATIONS_END_BIT_EXT = 0x00000001,
-   VK_PRESENT_STAGE_REQUEST_DEQUEUED_BIT_EXT = 0x00000002,
-   VK_PRESENT_STAGE_IMAGE_FIRST_PIXEL_OUT_BIT_EXT = 0x00000004,
-   VK_PRESENT_STAGE_IMAGE_FIRST_PIXEL_VISIBLE_BIT_EXT = 0x00000008,
-} VkPresentStageFlagBitsEXT;
-
-typedef struct VkSwapchainTimingPropertiesEXT
-{
-   VkStructureType sType;
-   const void *pNext;
-   uint64_t refreshDuration;
-   uint64_t refreshInterval;
-} VkSwapchainTimingPropertiesEXT;
-
-typedef struct VkSwapchainTimeDomainPropertiesEXT
-{
-   VkStructureType sType;
-   void *pNext;
-   uint32_t timeDomainCount;
-   VkTimeDomainEXT *pTimeDomains;
-   uint64_t *pTimeDomainIds;
-} VkSwapchainTimeDomainPropertiesEXT;
-
-typedef struct VkSwapchainCalibratedTimestampInfoEXT
-{
-   VkStructureType sType;
-   const void *pNext;
-   VkSwapchainKHR swapchain;
-   VkPresentStageFlagsEXT presentStage;
-   uint64_t timeDomainId;
-} VkSwapchainCalibratedTimestampInfoEXT;
-
-typedef struct VkPresentStageTimeEXT
-{
-   VkPresentStageFlagsEXT stage;
-   uint64_t time;
-} VkPresentStageTimeEXT;
-
-typedef struct VkPastPresentationTimingEXT
-{
-   VkStructureType sType;
-   void *pNext;
-   uint64_t presentId;
-   uint64_t targetTime;
-   uint32_t presentStageCount;
-   VkPresentStageTimeEXT *pPresentStages;
-   VkTimeDomainKHR timeDomain;
-   uint64_t timeDomainId;
-   VkBool32 reportComplete;
-} VkPastPresentationTimingEXT;
-
-typedef struct VkPastPresentationTimingPropertiesEXT
-{
-   VkStructureType sType;
-   const void *pNext;
-   uint64_t timingPropertiesCounter;
-   uint64_t timeDomainsCounter;
-   uint32_t presentationTimingCount;
-   VkPastPresentationTimingEXT *pPresentationTimings;
-} VkPastPresentationTimingPropertiesEXT;
-
-typedef VkFlags VkPastPresentationTimingFlagsEXT;
-
-typedef enum VkPastPresentationTimingFlagBitsEXT
-{
-   VK_PAST_PRESENTATION_TIMING_ALLOW_PARTIAL_RESULTS_BIT_EXT = 0x00000001,
-   VK_PAST_PRESENTATION_TIMING_ALLOW_OUT_OF_ORDER_RESULTS_BIT_EXT = 0x00000002,
-} VkPastPresentationTimingFlagBitsEXT;
-
-typedef enum VkPresentTimingInfoFlagBitsEXT
-{
-   VK_PRESENT_TIMING_INFO_PRESENT_AT_RELATIVE_TIME_BIT_EXT = 0x00000001,
-   VK_PRESENT_TIMING_INFO_PRESENT_AT_NEAREST_REFRESH_CYCLE_BIT_EXT = 0x00000002,
-} VkPresentTimingInfoFlagBitsEXT;
-
-typedef struct VkPastPresentationTimingInfoEXT
-{
-   VkStructureType sType;
-   const void *pNext;
-   VkPastPresentationTimingFlagsEXT flags;
-   VkSwapchainKHR swapchain;
-} VkPastPresentationTimingInfoEXT;
-
-typedef struct VkPresentTimingInfoEXT
-{
-   VkStructureType sType;
-   const void *pNext;
-   VkPresentTimingInfoFlagsEXT flags;
-   uint64_t targetTime;
-   uint64_t timeDomainId;
-   VkPresentStageFlagsEXT presentStageQueries;
-} VkPresentTimingInfoEXT;
-
-typedef struct VkPresentTimingsInfoEXT
-{
-   VkStructureType sType;
-   const void *pNext;
-   uint32_t swapchainCount;
-   const VkPresentTimingInfoEXT *pTimingInfos;
-} VkPresentTimingsInfoEXT;
-
-typedef VkResult(VKAPI_PTR *PFN_vkGetSwapchainTimeDomainPropertiesEXT)(
-   VkDevice device, VkSwapchainKHR swapchain, VkSwapchainTimeDomainPropertiesEXT *pSwapchainTimeDomainProperties,
-   uint64_t *pTimeDomainsCounter);
-
-typedef VkResult(VKAPI_PTR *PFN_vkGetSwapchainTimingPropertiesEXT)(
-   VkDevice device, VkSwapchainKHR swapchain, VkSwapchainTimingPropertiesEXT *pSwapchainTimingProperties,
-   uint64_t *pSwapchainTimingPropertiesCounter);
-
-typedef VkResult(VKAPI_PTR *PFN_vkSetSwapchainPresentTimingQueueSizeEXT)(VkDevice device, VkSwapchainKHR swapchain,
-                                                                         uint32_t size);
-
-typedef VkResult(VKAPI_PTR *PFN_vkGetPastPresentationTimingEXT)(
-   VkDevice device, const VkPastPresentationTimingInfoEXT *pPastPresentationTimingInfo,
-   VkPastPresentationTimingPropertiesEXT *pPastPresentationTimingProperties);
-
 VWL_VKAPI_CALL(VkResult)
 wsi_layer_vkSetSwapchainPresentTimingQueueSizeEXT(VkDevice device, VkSwapchainKHR swapchain,
                                                   uint32_t size) VWL_API_POST;
@@ -210,4 +52,4 @@ wsi_layer_vkGetPastPresentationTimingEXT(
    VkDevice device, const VkPastPresentationTimingInfoEXT *pPastPresentationTimingInfo,
    VkPastPresentationTimingPropertiesEXT *pPastPresentationTimingProperties) VWL_API_POST;
 
-#endif
\ No newline at end of file
+#endif