diff --git a/renderdoc/driver/d3d12/d3d12_device_wrap.cpp b/renderdoc/driver/d3d12/d3d12_device_wrap.cpp
index cacbe7383..3b465fbf4 100644
--- a/renderdoc/driver/d3d12/d3d12_device_wrap.cpp
+++ b/renderdoc/driver/d3d12/d3d12_device_wrap.cpp
@@ -838,14 +838,16 @@ bool WrappedID3D12Device::Serialise_CreateDescriptorHeap(
 
   if(IsReplayingAndReading())
   {
+    D3D12_DESCRIPTOR_HEAP_DESC PatchedDesc = Descriptor;
+
     // inflate the heap so we can insert our own descriptors at the end
     // while patching, because DX12 has a stupid limitation to not be able
     // to set multiple descriptor heaps at once of the same type
-    if(Descriptor.Type == D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV)
+    if(PatchedDesc.Type == D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV)
     {
       if(m_D3D12Opts.ResourceBindingTier == D3D12_RESOURCE_BINDING_TIER_3 ||
-         Descriptor.NumDescriptors + 16 <= 1000000)
-        Descriptor.NumDescriptors += 16;
+         PatchedDesc.NumDescriptors + 16 <= 1000000)
+        PatchedDesc.NumDescriptors += 16;
       else
         RDCERR(
             "RenderDoc needs extra descriptors for patching during analysis,"
@@ -853,7 +855,7 @@ bool WrappedID3D12Device::Serialise_CreateDescriptorHeap(
     }
 
     ID3D12DescriptorHeap *ret = NULL;
-    HRESULT hr = m_pDevice->CreateDescriptorHeap(&Descriptor, guid, (void **)&ret);
+    HRESULT hr = m_pDevice->CreateDescriptorHeap(&PatchedDesc, guid, (void **)&ret);
 
     if(FAILED(hr))
     {
diff --git a/renderdoc/driver/d3d12/d3d12_initstate.cpp b/renderdoc/driver/d3d12/d3d12_initstate.cpp
index 3061ea919..7a51dad1b 100644
--- a/renderdoc/driver/d3d12/d3d12_initstate.cpp
+++ b/renderdoc/driver/d3d12/d3d12_initstate.cpp
@@ -601,6 +601,9 @@ bool D3D12ResourceManager::Serialise_InitialState(SerialiserType &ser, ResourceI
 
       UINT increment = m_Device->GetDescriptorHandleIncrementSize(desc.Type);
 
+      // only iterate over the 'real' number of descriptors, not the number after we've patched
+      desc.NumDescriptors = heap->GetNumDescriptors();
+
       for(uint32_t i = 0; i < RDCMIN(numElems, desc.NumDescriptors); i++)
       {
         Descriptors[i].Create(desc.Type, m_Device, handle);
@@ -1024,14 +1027,14 @@ void D3D12ResourceManager::Apply_InitialState(ID3D12DeviceChild *live,
 
   if(type == Resource_DescriptorHeap)
   {
-    ID3D12DescriptorHeap *dstheap = (ID3D12DescriptorHeap *)live;
-    ID3D12DescriptorHeap *srcheap = (ID3D12DescriptorHeap *)data.resource;
+    WrappedID3D12DescriptorHeap *dstheap = (WrappedID3D12DescriptorHeap *)live;
+    WrappedID3D12DescriptorHeap *srcheap = (WrappedID3D12DescriptorHeap *)data.resource;
 
     if(srcheap)
     {
       // copy the whole heap
       m_Device->CopyDescriptorsSimple(
-          srcheap->GetDesc().NumDescriptors, dstheap->GetCPUDescriptorHandleForHeapStart(),
+          srcheap->GetNumDescriptors(), dstheap->GetCPUDescriptorHandleForHeapStart(),
           srcheap->GetCPUDescriptorHandleForHeapStart(), srcheap->GetDesc().Type);
     }
   }