diff --git a/renderdoc/driver/shaders/dxbc/dxbc_disassemble.cpp b/renderdoc/driver/shaders/dxbc/dxbc_disassemble.cpp
index fbf09f6d6..7c3eab369 100644
--- a/renderdoc/driver/shaders/dxbc/dxbc_disassemble.cpp
+++ b/renderdoc/driver/shaders/dxbc/dxbc_disassemble.cpp
@@ -294,7 +294,7 @@ void DXBCFile::FetchTypeVersion()
   m_Version.Minor = VersionToken::MinorVersion.Get(cur[0]);
 }
 
-void DXBCFile::FetchThreadDim()
+void DXBCFile::FetchComputeProperties()
 {
   if(m_HexDump.empty())
     return;
@@ -320,7 +320,47 @@ void DXBCFile::FetchThreadDim()
       DispatchThreadsDimension[0] = cur[1];
       DispatchThreadsDimension[1] = cur[2];
       DispatchThreadsDimension[2] = cur[3];
-      break;
+    }
+    else if(op == OPCODE_DCL_INPUT)
+    {
+      OperandType type = Operand::Type.Get(cur[1]);
+
+      SigParameter param;
+
+      param.compType = CompType::UInt;
+      param.regIndex = ~0U;
+
+      switch(type)
+      {
+        case TYPE_INPUT_THREAD_ID:
+          param.systemValue = ShaderBuiltin::DispatchThreadIndex;
+          param.compCount = 3;
+          param.regChannelMask = param.channelUsedMask = 0x7;
+          param.semanticIdxName = param.semanticName = "vThreadID";
+          m_InputSig.push_back(param);
+          break;
+        case TYPE_INPUT_THREAD_GROUP_ID:
+          param.systemValue = ShaderBuiltin::GroupIndex;
+          param.compCount = 3;
+          param.regChannelMask = param.channelUsedMask = 0x7;
+          param.semanticIdxName = param.semanticName = "vThreadGroupID";
+          m_InputSig.push_back(param);
+          break;
+        case TYPE_INPUT_THREAD_ID_IN_GROUP:
+          param.systemValue = ShaderBuiltin::GroupThreadIndex;
+          param.compCount = 3;
+          param.regChannelMask = param.channelUsedMask = 0x7;
+          param.semanticIdxName = param.semanticName = "vThreadIDInGroup";
+          m_InputSig.push_back(param);
+          break;
+        case TYPE_INPUT_THREAD_ID_IN_GROUP_FLATTENED:
+          param.systemValue = ShaderBuiltin::GroupFlatIndex;
+          param.compCount = 1;
+          param.regChannelMask = param.channelUsedMask = 0x1;
+          param.semanticIdxName = param.semanticName = "vThreadIDInGroupFlattened";
+          m_InputSig.push_back(param);
+          break;
+      }
     }
 
     if(op == OPCODE_CUSTOMDATA)
diff --git a/renderdoc/driver/shaders/dxbc/dxbc_inspect.cpp b/renderdoc/driver/shaders/dxbc/dxbc_inspect.cpp
index ece629893..51fb10a58 100644
--- a/renderdoc/driver/shaders/dxbc/dxbc_inspect.cpp
+++ b/renderdoc/driver/shaders/dxbc/dxbc_inspect.cpp
@@ -883,12 +883,6 @@ DXBCFile::DXBCFile(const void *ByteCode, size_t ByteCodeLength)
     m_GuessedResources = true;
   }
 
-  // make sure to fetch the dispatch threads dimension from disassembly
-  if(!m_Disassembled && m_Type == D3D11_ShaderType_Compute)
-  {
-    FetchThreadDim();
-  }
-
   for(uint32_t chunkIdx = 0; chunkIdx < header->numChunks; chunkIdx++)
   {
     uint32_t *fourcc = (uint32_t *)(data + chunkOffsets[chunkIdx]);
@@ -1067,6 +1061,12 @@ DXBCFile::DXBCFile(const void *ByteCode, size_t ByteCodeLength)
     }
   }
 
+  // make sure to fetch the dispatch threads dimension from disassembly
+  if(!m_Disassembled && m_Type == D3D11_ShaderType_Compute)
+  {
+    FetchComputeProperties();
+  }
+
   // initialise debug chunks last
   for(uint32_t chunkIdx = 0; chunkIdx < header->numChunks; chunkIdx++)
   {
diff --git a/renderdoc/driver/shaders/dxbc/dxbc_inspect.h b/renderdoc/driver/shaders/dxbc/dxbc_inspect.h
index 5abb66c86..b33b42b13 100644
--- a/renderdoc/driver/shaders/dxbc/dxbc_inspect.h
+++ b/renderdoc/driver/shaders/dxbc/dxbc_inspect.h
@@ -403,7 +403,7 @@ private:
   DXBCFile(const DXBCFile &o);
   DXBCFile &operator=(const DXBCFile &o);
 
-  void FetchThreadDim();
+  void FetchComputeProperties();
   void FetchTypeVersion();
   void DisassembleHexDump();
   void MakeDisassemblyString();