diff --git a/src/dawn_native/CommandEncoder.cpp b/src/dawn_native/CommandEncoder.cpp
index f9a805e185..f2d42691ba 100644
--- a/src/dawn_native/CommandEncoder.cpp
+++ b/src/dawn_native/CommandEncoder.cpp
@@ -62,19 +62,22 @@ namespace dawn_native {
             return {};
         }
 
-        bool FitsInBuffer(const BufferBase* buffer, uint64_t offset, uint64_t size) {
+        MaybeError ValidateCopySizeFitsInBuffer(const Ref<BufferBase>& buffer,
+                                                uint64_t offset,
+                                                uint64_t size) {
             uint64_t bufferSize = buffer->GetSize();
-            return offset <= bufferSize && (size <= (bufferSize - offset));
-        }
-
-        MaybeError ValidateCopySizeFitsInBuffer(const BufferCopy& bufferCopy, uint64_t dataSize) {
-            if (!FitsInBuffer(bufferCopy.buffer.Get(), bufferCopy.offset, dataSize)) {
+            bool fitsInBuffer = offset <= bufferSize && (size <= (bufferSize - offset));
+            if (!fitsInBuffer) {
                 return DAWN_VALIDATION_ERROR("Copy would overflow the buffer");
             }
 
             return {};
         }
 
+        MaybeError ValidateCopySizeFitsInBuffer(const BufferCopy& bufferCopy, uint64_t dataSize) {
+            return ValidateCopySizeFitsInBuffer(bufferCopy.buffer, bufferCopy.offset, dataSize);
+        }
+
         MaybeError ValidateB2BCopySizeAlignment(uint64_t dataSize,
                                                 uint64_t srcOffset,
                                                 uint64_t dstOffset) {
@@ -690,10 +693,10 @@ namespace dawn_native {
 
         CopyBufferToBufferCmd* copy =
             mAllocator.Allocate<CopyBufferToBufferCmd>(Command::CopyBufferToBuffer);
-        copy->source.buffer = source;
-        copy->source.offset = sourceOffset;
-        copy->destination.buffer = destination;
-        copy->destination.offset = destinationOffset;
+        copy->source = source;
+        copy->sourceOffset = sourceOffset;
+        copy->destination = destination;
+        copy->destinationOffset = destinationOffset;
         copy->size = size;
     }
 
@@ -877,18 +880,20 @@ namespace dawn_native {
                 case Command::CopyBufferToBuffer: {
                     CopyBufferToBufferCmd* copy = mIterator.NextCommand<CopyBufferToBufferCmd>();
 
-                    DAWN_TRY(ValidateCopySizeFitsInBuffer(copy->source, copy->size));
-                    DAWN_TRY(ValidateCopySizeFitsInBuffer(copy->destination, copy->size));
-                    DAWN_TRY(ValidateB2BCopySizeAlignment(copy->size, copy->source.offset,
-                                                          copy->destination.offset));
+                    DAWN_TRY(
+                        ValidateCopySizeFitsInBuffer(copy->source, copy->sourceOffset, copy->size));
+                    DAWN_TRY(ValidateCopySizeFitsInBuffer(copy->destination,
+                                                          copy->destinationOffset, copy->size));
+                    DAWN_TRY(ValidateB2BCopySizeAlignment(copy->size, copy->sourceOffset,
+                                                          copy->destinationOffset));
 
-                    DAWN_TRY(ValidateCanUseAs(copy->source.buffer.Get(),
-                                              dawn::BufferUsageBit::TransferSrc));
-                    DAWN_TRY(ValidateCanUseAs(copy->destination.buffer.Get(),
+                    DAWN_TRY(
+                        ValidateCanUseAs(copy->source.Get(), dawn::BufferUsageBit::TransferSrc));
+                    DAWN_TRY(ValidateCanUseAs(copy->destination.Get(),
                                               dawn::BufferUsageBit::TransferDst));
 
-                    mResourceUsages.topLevelBuffers.insert(copy->source.buffer.Get());
-                    mResourceUsages.topLevelBuffers.insert(copy->destination.buffer.Get());
+                    mResourceUsages.topLevelBuffers.insert(copy->source.Get());
+                    mResourceUsages.topLevelBuffers.insert(copy->destination.Get());
                 } break;
 
                 case Command::CopyBufferToTexture: {
diff --git a/src/dawn_native/Commands.h b/src/dawn_native/Commands.h
index e36262299a..53d6047c47 100644
--- a/src/dawn_native/Commands.h
+++ b/src/dawn_native/Commands.h
@@ -102,8 +102,10 @@ namespace dawn_native {
     };
 
     struct CopyBufferToBufferCmd {
-        BufferCopy source;
-        BufferCopy destination;
+        Ref<BufferBase> source;
+        uint64_t sourceOffset;
+        Ref<BufferBase> destination;
+        uint64_t destinationOffset;
         uint64_t size;
     };
 
diff --git a/src/dawn_native/d3d12/CommandBufferD3D12.cpp b/src/dawn_native/d3d12/CommandBufferD3D12.cpp
index d9c7d52fb8..6b9f8e631c 100644
--- a/src/dawn_native/d3d12/CommandBufferD3D12.cpp
+++ b/src/dawn_native/d3d12/CommandBufferD3D12.cpp
@@ -469,15 +469,15 @@ namespace dawn_native { namespace d3d12 {
 
                 case Command::CopyBufferToBuffer: {
                     CopyBufferToBufferCmd* copy = mCommands.NextCommand<CopyBufferToBufferCmd>();
-                    Buffer* srcBuffer = ToBackend(copy->source.buffer.Get());
-                    Buffer* dstBuffer = ToBackend(copy->destination.buffer.Get());
+                    Buffer* srcBuffer = ToBackend(copy->source.Get());
+                    Buffer* dstBuffer = ToBackend(copy->destination.Get());
 
                     srcBuffer->TransitionUsageNow(commandList, dawn::BufferUsageBit::TransferSrc);
                     dstBuffer->TransitionUsageNow(commandList, dawn::BufferUsageBit::TransferDst);
 
                     commandList->CopyBufferRegion(
-                        dstBuffer->GetD3D12Resource().Get(), copy->destination.offset,
-                        srcBuffer->GetD3D12Resource().Get(), copy->source.offset, copy->size);
+                        dstBuffer->GetD3D12Resource().Get(), copy->destinationOffset,
+                        srcBuffer->GetD3D12Resource().Get(), copy->sourceOffset, copy->size);
                 } break;
 
                 case Command::CopyBufferToTexture: {
diff --git a/src/dawn_native/metal/CommandBufferMTL.mm b/src/dawn_native/metal/CommandBufferMTL.mm
index a0a35491a3..7cc8897d58 100644
--- a/src/dawn_native/metal/CommandBufferMTL.mm
+++ b/src/dawn_native/metal/CommandBufferMTL.mm
@@ -348,14 +348,12 @@ namespace dawn_native { namespace metal {
 
                 case Command::CopyBufferToBuffer: {
                     CopyBufferToBufferCmd* copy = mCommands.NextCommand<CopyBufferToBufferCmd>();
-                    auto& src = copy->source;
-                    auto& dst = copy->destination;
 
                     encoders.EnsureBlit(commandBuffer);
-                    [encoders.blit copyFromBuffer:ToBackend(src.buffer)->GetMTLBuffer()
-                                     sourceOffset:src.offset
-                                         toBuffer:ToBackend(dst.buffer)->GetMTLBuffer()
-                                destinationOffset:dst.offset
+                    [encoders.blit copyFromBuffer:ToBackend(copy->source)->GetMTLBuffer()
+                                     sourceOffset:copy->sourceOffset
+                                         toBuffer:ToBackend(copy->destination)->GetMTLBuffer()
+                                destinationOffset:copy->destinationOffset
                                              size:copy->size];
                 } break;
 
diff --git a/src/dawn_native/opengl/CommandBufferGL.cpp b/src/dawn_native/opengl/CommandBufferGL.cpp
index a1b5e547c4..7c5a8dc9de 100644
--- a/src/dawn_native/opengl/CommandBufferGL.cpp
+++ b/src/dawn_native/opengl/CommandBufferGL.cpp
@@ -360,13 +360,11 @@ namespace dawn_native { namespace opengl {
 
                 case Command::CopyBufferToBuffer: {
                     CopyBufferToBufferCmd* copy = mCommands.NextCommand<CopyBufferToBufferCmd>();
-                    auto& src = copy->source;
-                    auto& dst = copy->destination;
 
-                    glBindBuffer(GL_PIXEL_PACK_BUFFER, ToBackend(src.buffer)->GetHandle());
-                    glBindBuffer(GL_PIXEL_UNPACK_BUFFER, ToBackend(dst.buffer)->GetHandle());
-                    glCopyBufferSubData(GL_PIXEL_PACK_BUFFER, GL_PIXEL_UNPACK_BUFFER, src.offset,
-                                        dst.offset, copy->size);
+                    glBindBuffer(GL_PIXEL_PACK_BUFFER, ToBackend(copy->source)->GetHandle());
+                    glBindBuffer(GL_PIXEL_UNPACK_BUFFER, ToBackend(copy->destination)->GetHandle());
+                    glCopyBufferSubData(GL_PIXEL_PACK_BUFFER, GL_PIXEL_UNPACK_BUFFER,
+                                        copy->sourceOffset, copy->destinationOffset, copy->size);
 
                     glBindBuffer(GL_PIXEL_PACK_BUFFER, 0);
                     glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
diff --git a/src/dawn_native/vulkan/CommandBufferVk.cpp b/src/dawn_native/vulkan/CommandBufferVk.cpp
index 89fbbac4c0..a04bec72e8 100644
--- a/src/dawn_native/vulkan/CommandBufferVk.cpp
+++ b/src/dawn_native/vulkan/CommandBufferVk.cpp
@@ -301,21 +301,19 @@ namespace dawn_native { namespace vulkan {
             switch (type) {
                 case Command::CopyBufferToBuffer: {
                     CopyBufferToBufferCmd* copy = mCommands.NextCommand<CopyBufferToBufferCmd>();
-                    auto& src = copy->source;
-                    auto& dst = copy->destination;
+                    Buffer* srcBuffer = ToBackend(copy->source.Get());
+                    Buffer* dstBuffer = ToBackend(copy->destination.Get());
 
-                    ToBackend(src.buffer)
-                        ->TransitionUsageNow(commands, dawn::BufferUsageBit::TransferSrc);
-                    ToBackend(dst.buffer)
-                        ->TransitionUsageNow(commands, dawn::BufferUsageBit::TransferDst);
+                    srcBuffer->TransitionUsageNow(commands, dawn::BufferUsageBit::TransferSrc);
+                    dstBuffer->TransitionUsageNow(commands, dawn::BufferUsageBit::TransferDst);
 
                     VkBufferCopy region;
-                    region.srcOffset = src.offset;
-                    region.dstOffset = dst.offset;
+                    region.srcOffset = copy->sourceOffset;
+                    region.dstOffset = copy->destinationOffset;
                     region.size = copy->size;
 
-                    VkBuffer srcHandle = ToBackend(src.buffer)->GetHandle();
-                    VkBuffer dstHandle = ToBackend(dst.buffer)->GetHandle();
+                    VkBuffer srcHandle = srcBuffer->GetHandle();
+                    VkBuffer dstHandle = dstBuffer->GetHandle();
                     device->fn.CmdCopyBuffer(commands, srcHandle, dstHandle, 1, &region);
                 } break;