diff --git a/gpu-vulkan.cabal b/gpu-vulkan.cabal
--- a/gpu-vulkan.cabal
+++ b/gpu-vulkan.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           gpu-vulkan
-version:        0.1.0.165
+version:        0.1.0.166
 synopsis:       Vulkan library
 description:    Please see the README on GitHub at <https://github.com/YoshikuniJujo/gpu-vulkan#readme>
 category:       GPU
diff --git a/src/Gpu/Vulkan/Pipeline/ShaderStage/Internal.hs b/src/Gpu/Vulkan/Pipeline/ShaderStage/Internal.hs
--- a/src/Gpu/Vulkan/Pipeline/ShaderStage/Internal.hs
+++ b/src/Gpu/Vulkan/Pipeline/ShaderStage/Internal.hs
@@ -53,7 +53,7 @@
 	createInfoModule :: (
 		ShaderModule.CreateInfo mnsm sknd, TPMaybe.M (U2 AllocationCallbacks.A) mac ),
 	createInfoName :: BS.ByteString,
-	createInfoSpecializationInfo :: Maybe (HeteroParList.L vs) }
+	createInfoSpecializationInfo :: HeteroParList.L vs }
 
 allocationCallbacksFromCreateInfo ::
 	CreateInfo mn mnsm sknd mac vs ->