4 files changed, 10 insertions, 6 deletions
diff --git a/tools/gfx/d3d12/render-d3d12.cpp b/tools/gfx/d3d12/render-d3d12.cpp
index 98f56958c..e6168f17c 100644
--- a/tools/gfx/d3d12/render-d3d12.cpp
+++ b/tools/gfx/d3d12/render-d3d12.cpp
@@ -6408,10 +6408,11 @@ RefPtr<BufferResource> ShaderTableImpl::createDeviceBuffer(
 // a `CommandBuffer` created from the heap. We need to break the cycle upon
 // the public reference count of a command buffer dropping to 0.
 
-ICommandBuffer* CommandBufferImpl::getInterface(const Guid& guid)
+ICommandBufferD3D12* CommandBufferImpl::getInterface(const Guid& guid)
 {
-    if (guid == GfxGUID::IID_ISlangUnknown || guid == GfxGUID::IID_ICommandBuffer)
-        return static_cast<ICommandBuffer*>(this);
+    if (guid == GfxGUID::IID_ISlangUnknown || guid == GfxGUID::IID_ICommandBuffer ||
+        guid == GfxGUID::IID_ICommandBufferD3D12)
+        return static_cast<ICommandBufferD3D12*>(this);
     return nullptr;
 }
 
diff --git a/tools/gfx/d3d12/render-d3d12.h b/tools/gfx/d3d12/render-d3d12.h
index 5dae6a383..c8def3217 100644
--- a/tools/gfx/d3d12/render-d3d12.h
+++ b/tools/gfx/d3d12/render-d3d12.h
@@ -1641,7 +1641,7 @@ public:
 #endif
 
 class CommandBufferImpl
-    : public ICommandBuffer
+    : public ICommandBufferD3D12
     , public ComObject
 {
 public:
@@ -1650,7 +1650,7 @@ public:
     // the public reference count of a command buffer dropping to 0.
     SLANG_COM_OBJECT_IUNKNOWN_ALL
 
-    ICommandBuffer* getInterface(const Guid& guid);
+    ICommandBufferD3D12* getInterface(const Guid& guid);
     virtual void comFree() override { m_transientHeap.breakStrongReference(); }
 
     virtual SLANG_NO_THROW Result SLANG_MCALL getNativeHandle(InteropHandle* handle) override;
@@ -1670,7 +1670,7 @@ public:
 
     void bindDescriptorHeaps();
 
-    void invalidateDescriptorHeapBinding() { m_descriptorHeapsBound = false; }
+    virtual SLANG_NO_THROW void SLANG_MCALL invalidateDescriptorHeapBinding() override { m_descriptorHeapsBound = false; }
 
     void reinit();
 
diff --git a/tools/gfx/renderer-shared.cpp b/tools/gfx/renderer-shared.cpp
index dd949efd4..5d62f7fba 100644
--- a/tools/gfx/renderer-shared.cpp
+++ b/tools/gfx/renderer-shared.cpp
@@ -28,6 +28,8 @@ const Slang::Guid GfxGUID::IID_IShaderObject = SLANG_UUID_IShaderObject;
 const Slang::Guid GfxGUID::IID_IRenderPassLayout = SLANG_UUID_IRenderPassLayout;
 const Slang::Guid GfxGUID::IID_IRayTracingCommandEncoder = SLANG_UUID_IRayTracingCommandEncoder;
 const Slang::Guid GfxGUID::IID_ICommandBuffer = SLANG_UUID_ICommandBuffer;
+const Slang::Guid GfxGUID::IID_ICommandBufferD3D12 = SLANG_UUID_ICommandBufferD3D12;
+
 const Slang::Guid GfxGUID::IID_ICommandQueue = SLANG_UUID_ICommandQueue;
 const Slang::Guid GfxGUID::IID_IQueryPool = SLANG_UUID_IQueryPool;
 const Slang::Guid GfxGUID::IID_IAccelerationStructure = SLANG_UUID_IAccelerationStructure;
diff --git a/tools/gfx/renderer-shared.h b/tools/gfx/renderer-shared.h
index f4ca259e7..601a8ee85 100644
--- a/tools/gfx/renderer-shared.h
+++ b/tools/gfx/renderer-shared.h
@@ -35,6 +35,7 @@ struct GfxGUID
     static const Slang::Guid IID_IResourceCommandEncoder;
     static const Slang::Guid IID_IRayTracingCommandEncoder;
     static const Slang::Guid IID_ICommandBuffer;
+    static const Slang::Guid IID_ICommandBufferD3D12;
     static const Slang::Guid IID_ICommandQueue;
     static const Slang::Guid IID_IQueryPool;
     static const Slang::Guid IID_IAccelerationStructure;