diff --git a/win32/CD3DCG.cpp b/win32/CD3DCG.cpp
index 555e2a4b..ed9dc716 100644
--- a/win32/CD3DCG.cpp
+++ b/win32/CD3DCG.cpp
@@ -430,7 +430,7 @@ void CD3DCG::Render(LPDIRECT3DTEXTURE9 &origTex, float2 textureSize,
 	pDevice->SetPixelShader(NULL);
 }
 
-static D3DMATRIX matrix_mul(D3DMATRIX& mat1, D3DMATRIX& mat2)
+static D3DMATRIX matrix_mul(D3DMATRIX mat1, D3DMATRIX mat2)
 {
 	D3DMATRIX out;
 	for (auto y = 0; y < 4; y++)
@@ -448,7 +448,7 @@ static D3DMATRIX matrix_mul(D3DMATRIX& mat1, D3DMATRIX& mat2)
 	return out;
 }
 
-static D3DMATRIX matrix_transpose(D3DMATRIX& mat)
+static D3DMATRIX matrix_transpose(D3DMATRIX mat)
 {
 	D3DMATRIX out;
 	for (auto y = 0; y < 4; y++)
diff --git a/win32/CVulkan.cpp b/win32/CVulkan.cpp
index 70c3c2ec..7b4097e2 100644
--- a/win32/CVulkan.cpp
+++ b/win32/CVulkan.cpp
@@ -27,7 +27,7 @@ bool CVulkan::Initialize(HWND hWnd)
     if (GUI.shaderEnabled && GUI.OGLshaderFileName && GUI.OGLshaderFileName[0])
     {
         shaderchain = std::make_unique<Vulkan::ShaderChain>(context.get());
-        std::string shaderstring = _tToChar(GUI.OGLshaderFileName);
+        std::string shaderstring = std::string(_tToChar(GUI.OGLshaderFileName));
         if (!shaderchain->load_shader_preset(shaderstring))
         {
             shaderchain.reset();