diff --git a/gpu-vulkan-middle.cabal b/gpu-vulkan-middle.cabal
--- a/gpu-vulkan-middle.cabal
+++ b/gpu-vulkan-middle.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           gpu-vulkan-middle
-version:        0.1.0.63
+version:        0.1.0.64
 synopsis:       Medium wrapper for Vulkan API
 description:    Please see the README on GitHub at <https://github.com/YoshikuniJujo/gpu-vulkan-middle#readme>
 category:       GPU
diff --git a/src/Gpu/Vulkan/PhysicalDevice/Middle/Internal.hsc b/src/Gpu/Vulkan/PhysicalDevice/Middle/Internal.hsc
--- a/src/Gpu/Vulkan/PhysicalDevice/Middle/Internal.hsc
+++ b/src/Gpu/Vulkan/PhysicalDevice/Middle/Internal.hsc
@@ -171,6 +171,12 @@
 
 deriving instance Show (TMaybe.M mn) => Show (Features2 mn)
 
+instance WithPoked (TMaybe.M mn) => WithPoked (Features2 mn) where
+	withPoked' (Features2 mn fs) f = alloca \pfs2 -> do
+		withPoked' mn \spn -> withPtrS spn \pn ->
+			poke pfs2 $ C.Features2 () (castPtr pn) (featuresToCore fs)
+		f . ptrS $ castPtr pfs2
+
 features2FromCore :: ReadChain mn => C.Features2 -> IO (Features2 mn)
 features2FromCore C.Features2 {
 	C.features2PNext = pnxt,