diff --git a/renderdoc/driver/d3d12/d3d12_debug.cpp b/renderdoc/driver/d3d12/d3d12_debug.cpp
index df3a2504e..0cbac693e 100644
--- a/renderdoc/driver/d3d12/d3d12_debug.cpp
+++ b/renderdoc/driver/d3d12/d3d12_debug.cpp
@@ -146,7 +146,7 @@ D3D12DebugManager::D3D12DebugManager(WrappedID3D12Device *wrapper)
   desc.NumDescriptors = rtvCount;
   desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_RTV;
 
-  RDCCOMPILE_ASSERT(LAST_WIN_RTV < rtvCount, "Increase size of RTV heap");
+  RDCCOMPILE_ASSERT(MAX_RTV_SLOT < rtvCount, "Increase size of RTV heap");
 
   hr = m_pDevice->CreateDescriptorHeap(&desc, __uuidof(ID3D12DescriptorHeap), (void **)&rtvHeap);
   m_pDevice->InternalRef();
@@ -163,7 +163,7 @@ D3D12DebugManager::D3D12DebugManager(WrappedID3D12Device *wrapper)
   desc.NumDescriptors = dsvCount;
   desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_DSV;
 
-  RDCCOMPILE_ASSERT(LAST_WIN_DSV < dsvCount, "Increase size of DSV heap");
+  RDCCOMPILE_ASSERT(MAX_DSV_SLOT < dsvCount, "Increase size of DSV heap");
 
   hr = m_pDevice->CreateDescriptorHeap(&desc, __uuidof(ID3D12DescriptorHeap), (void **)&dsvHeap);
   m_pDevice->InternalRef();
@@ -175,10 +175,12 @@ D3D12DebugManager::D3D12DebugManager(WrappedID3D12Device *wrapper)
 
   rm->SetInternalResource(dsvHeap);
 
-  desc.NumDescriptors = 4096;
+  const uint32_t srvCount = 4096;
+
+  desc.NumDescriptors = srvCount;
   desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV;
 
-  RDCCOMPILE_ASSERT(MAX_SRV_SLOT < 4096, "Increase size of CBV/SRV/UAV heap");
+  RDCCOMPILE_ASSERT(MAX_SRV_SLOT < srvCount, "Increase size of CBV/SRV/UAV heap");
 
   hr = m_pDevice->CreateDescriptorHeap(&desc, __uuidof(ID3D12DescriptorHeap), (void **)&uavClearHeap);
   m_pDevice->InternalRef();
@@ -203,9 +205,13 @@ D3D12DebugManager::D3D12DebugManager(WrappedID3D12Device *wrapper)
 
   rm->SetInternalResource(cbvsrvuavHeap);
 
-  desc.NumDescriptors = 16;
+  const uint32_t samplerCount = 300;
+
+  desc.NumDescriptors = samplerCount;
   desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_SAMPLER;
 
+  RDCCOMPILE_ASSERT(MAX_SAMPLER_SLOT < samplerCount, "Increase size of sampler heap");
+
   hr = m_pDevice->CreateDescriptorHeap(&desc, __uuidof(ID3D12DescriptorHeap), (void **)&samplerHeap);
   m_pDevice->InternalRef();
 
diff --git a/renderdoc/driver/d3d12/d3d12_debug.h b/renderdoc/driver/d3d12/d3d12_debug.h
index 07e08d1b2..a8f6ed512 100644
--- a/renderdoc/driver/d3d12/d3d12_debug.h
+++ b/renderdoc/driver/d3d12/d3d12_debug.h
@@ -118,6 +118,8 @@ enum RTVSlot
   LAST_TMP_RTV = FIRST_TMP_RTV + 16,
   FIRST_WIN_RTV,
   LAST_WIN_RTV = FIRST_WIN_RTV + 768,
+
+  MAX_RTV_SLOT,
 };
 
 enum SamplerSlot
@@ -128,6 +130,7 @@ enum SamplerSlot
   SHADDEBUG_SAMPLER0,
   LAST_SHADDEBUG_SAMPLER = SHADDEBUG_SAMPLER0 + ShaderDebugConstants::COUNT_SAMPLERS_PER_DEBUG *
                                                     ShaderDebugConstants::MAX_SHADER_DEBUG_QUEUED_OPS,
+  MAX_SAMPLER_SLOT,
 };
 
 enum DSVSlot
@@ -138,6 +141,8 @@ enum DSVSlot
   TMP_DSV,
   FIRST_WIN_DSV,
   LAST_WIN_DSV = FIRST_WIN_DSV + 64,
+
+  MAX_DSV_SLOT
 };
 
 struct MeshDisplayPipelines