diff --git a/src/amd/vulkan/radv_device.c b/src/amd/vulkan/radv_device.c
index 72f6481f3ca..f419095666a 100644
--- a/src/amd/vulkan/radv_device.c
+++ b/src/amd/vulkan/radv_device.c
@@ -6190,6 +6190,9 @@ vk_icdNegotiateLoaderICDInterfaceVersion(uint32_t *pSupportedVersion)
     *        - The ICD must implement vkCreate{PLATFORM}SurfaceKHR(),
     *          vkDestroySurfaceKHR(), and other API which uses VKSurfaceKHR,
     *          because the loader no longer does so.
+    *
+    *    - Loader interface v4 differs from v3 in:
+    *        - The ICD must implement vk_icdGetPhysicalDeviceProcAddr().
     */
    *pSupportedVersion = MIN2(*pSupportedVersion, 4u);
    return VK_SUCCESS;