diff --git a/include/d3d12.idl b/include/d3d12.idl
index 5e35654d..19b984c1 100644
--- a/include/d3d12.idl
+++ b/include/d3d12.idl
@@ -2102,19 +2102,18 @@ interface ID3D12RootSignatureDeserializer : IUnknown
     const D3D12_ROOT_SIGNATURE_DESC *GetRootSignatureDesc();
 }
 
-cpp_quote("HRESULT WINAPI D3D12CreateRootSignatureDeserializer(")
-cpp_quote("const void *data, SIZE_T data_size, REFIID riid, void **deserializer);")
+[local] HRESULT __stdcall D3D12CreateRootSignatureDeserializer(
+        const void *data, SIZE_T data_size, REFIID iid, void **deserializer);
 
-cpp_quote("HRESULT WINAPI D3D12SerializeRootSignature(")
-cpp_quote("const D3D12_ROOT_SIGNATURE_DESC *root_signature,")
-cpp_quote("D3D_ROOT_SIGNATURE_VERSION version, ID3DBlob **blob, ID3DBlob **error_blob);")
+[local] HRESULT __stdcall D3D12SerializeRootSignature(
+        const D3D12_ROOT_SIGNATURE_DESC *root_signature_desc,
+        D3D_ROOT_SIGNATURE_VERSION version, ID3DBlob **blob, ID3DBlob **error_blob);
 
-cpp_quote("HRESULT WINAPI D3D12SerializeVersionedRootSignature(")
-cpp_quote("const D3D12_VERSIONED_ROOT_SIGNATURE_DESC *root_signature,")
-cpp_quote("ID3DBlob **blob, ID3DBlob **error_blob);")
+[local] HRESULT __stdcall D3D12SerializeVersionedRootSignature(
+        const D3D12_VERSIONED_ROOT_SIGNATURE_DESC *root_signature_desc,
+        ID3DBlob **blob, ID3DBlob **error_blob);
 
-cpp_quote("HRESULT WINAPI D3D12CreateDevice(IUnknown *adapter,")
-cpp_quote("D3D_FEATURE_LEVEL minimum_feature_level,")
-cpp_quote("REFIID riid, void **device);")
+[local] HRESULT __stdcall D3D12CreateDevice(IUnknown *adapter,
+        D3D_FEATURE_LEVEL minimum_feature_level, REFIID iid, void **device);
 
-cpp_quote("HRESULT WINAPI D3D12GetDebugInterface(REFIID riid, void **debug);")
+[local] HRESULT __stdcall D3D12GetDebugInterface(REFIID iid, void **debug);
diff --git a/include/vkd3d_windows.h b/include/vkd3d_windows.h
index 4ac4ed2a..09c30f69 100644
--- a/include/vkd3d_windows.h
+++ b/include/vkd3d_windows.h
@@ -138,13 +138,14 @@ typedef struct SECURITY_ATTRIBUTES SECURITY_ATTRIBUTES;
         ((type *)((char *)(address) - offsetof(type, field)))
 
 # ifdef __x86_64__
-#  define WINAPI __attribute__((ms_abi))
-#  define STDMETHODCALLTYPE __attribute__((ms_abi))
+#  define __stdcall __attribute__((ms_abi))
 # else
-#  define WINAPI __attribute__((__stdcall__))
-#  define STDMETHODCALLTYPE __attribute__((__stdcall__))
+#  define __stdcall __attribute__((__stdcall__))
 # endif
 
+# define WINAPI __stdcall
+# define STDMETHODCALLTYPE __stdcall
+
 # ifdef __GNUC__
 #  define DECLSPEC_SELECTANY __attribute__((weak))
 # endif