diff --git a/renderdoc/driver/d3d12/d3d12_device_wrap.cpp b/renderdoc/driver/d3d12/d3d12_device_wrap.cpp
index 20ea7c50c..1e331e7b1 100644
--- a/renderdoc/driver/d3d12/d3d12_device_wrap.cpp
+++ b/renderdoc/driver/d3d12/d3d12_device_wrap.cpp
@@ -840,15 +840,13 @@ void WrappedID3D12Device::CopyDescriptors(
   for(UINT i = 0; i < NumDestDescriptorRanges; i++)
     dstStarts[i] = Unwrap(pDestDescriptorRangeStarts[i]);
 
-  for(UINT i = 0; i < NumDestDescriptorRanges; i++)
+  for(UINT i = 0; i < NumSrcDescriptorRanges; i++)
     srcStarts[i] = Unwrap(pSrcDescriptorRangeStarts[i]);
 
   m_pDevice->CopyDescriptors(NumDestDescriptorRanges, dstStarts, pDestDescriptorRangeSizes,
                              NumSrcDescriptorRanges, srcStarts, pSrcDescriptorRangeSizes,
                              DescriptorHeapsType);
 
-  RDCUNIMPLEMENTED("CopyDescriptors does not copy our internal descriptor data");
-
   UINT srcRange = 0, dstRange = 0;
   UINT srcIdx = 0, dstIdx = 0;
 
@@ -873,13 +871,13 @@ void WrappedID3D12Device::CopyDescriptors(
         src = GetWrapped(pSrcDescriptorRangeStarts[srcRange]);
     }
 
-    if(dstIdx >= pDestDescriptorRangeSizes[srcRange])
+    if(dstIdx >= pDestDescriptorRangeSizes[dstRange])
     {
       dstRange++;
       dstIdx = 0;
 
       if(dstRange < NumDestDescriptorRanges)
-        dst = GetWrapped(pDestDescriptorRangeStarts[srcRange]);
+        dst = GetWrapped(pDestDescriptorRangeStarts[dstRange]);
     }
   }