diff --git a/renderdoc/driver/d3d12/d3d12_shader_cache.cpp b/renderdoc/driver/d3d12/d3d12_shader_cache.cpp
index 2a48a0509..1b6ee7fd6 100644
--- a/renderdoc/driver/d3d12/d3d12_shader_cache.cpp
+++ b/renderdoc/driver/d3d12/d3d12_shader_cache.cpp
@@ -569,9 +569,16 @@ rdcstr D3D12ShaderCache::GetShaderBlob(const char *source, const char *entry,
           {{"hlsl_texsample.h", texSampleBlob}, {"hlsl_cbuffers.h", cBufferBlob}});
 
       IDxcOperationResult *result = NULL;
+      uint32_t flags = DXBC::DecodeFlags(compileFlags) & ~D3DCOMPILE_NO_PRESHADER;
+      rdcarray<rdcwstr> argsData;
+      DXBC::EncodeDXCFlags(flags, argsData);
+      rdcarray<LPCWSTR> arguments;
+      for(const rdcwstr &arg : argsData)
+        arguments.push_back(arg.c_str());
+
       hr = compiler->Compile(sourceBlob, NULL, StringFormat::UTF82Wide(entry).c_str(),
-                             StringFormat::UTF82Wide(profile).c_str(), NULL, (UINT)0, NULL, 0,
-                             &includeHandler, &result);
+                             StringFormat::UTF82Wide(profile).c_str(), arguments.data(),
+                             arguments.count(), NULL, 0, &includeHandler, &result);
 
       SAFE_RELEASE(sourceBlob);
 
diff --git a/renderdoc/driver/shaders/dxbc/dxbc_container.cpp b/renderdoc/driver/shaders/dxbc/dxbc_container.cpp
index 599d76e83..23e9895ce 100644
--- a/renderdoc/driver/shaders/dxbc/dxbc_container.cpp
+++ b/renderdoc/driver/shaders/dxbc/dxbc_container.cpp
@@ -2194,6 +2194,59 @@ DXBCContainer::~DXBCContainer()
   SAFE_DELETE(m_Reflection);
 }
 
+struct DxcArg
+{
+  uint32_t bit;
+  const wchar_t *arg;
+} dxc_flags[] = {
+    {D3DCOMPILE_DEBUG, L"-Zi"},
+    {D3DCOMPILE_SKIP_VALIDATION, L"-Vd"},
+    {D3DCOMPILE_SKIP_OPTIMIZATION, L"-Od"},
+    {D3DCOMPILE_PACK_MATRIX_ROW_MAJOR, L"-Zpr"},
+    {D3DCOMPILE_PACK_MATRIX_COLUMN_MAJOR, L"-Zpc "},
+    {D3DCOMPILE_PARTIAL_PRECISION, L"-Gpp"},
+    {D3DCOMPILE_NO_PRESHADER, L"-Op"},
+    {D3DCOMPILE_AVOID_FLOW_CONTROL, L"-Gfa"},
+    {D3DCOMPILE_PREFER_FLOW_CONTROL, L"-Gfp"},
+    {D3DCOMPILE_ENABLE_STRICTNESS, L"-Ges"},
+    {D3DCOMPILE_ENABLE_BACKWARDS_COMPATIBILITY, L"-Gec"},
+    {D3DCOMPILE_IEEE_STRICTNESS, L"-Gis"},
+    {D3DCOMPILE_WARNINGS_ARE_ERRORS, L"-WX"},
+    {D3DCOMPILE_RESOURCES_MAY_ALIAS, L"-res_may_alias"},
+    {D3DCOMPILE_ALL_RESOURCES_BOUND, L"-all_resources_bound"},
+    {D3DCOMPILE_ENABLE_UNBOUNDED_DESCRIPTOR_TABLES, L"-enable_unbounded_descriptor_tables"},
+    {D3DCOMPILE_DEBUG_NAME_FOR_SOURCE, L"-Zss"},
+    {D3DCOMPILE_DEBUG_NAME_FOR_BINARY, L"-Zsb"},
+};
+
+void EncodeDXCFlags(uint32_t flags, rdcarray<rdcwstr> &args)
+{
+  for(const DxcArg &arg : dxc_flags)
+  {
+    if(flags & arg.bit)
+      args.push_back(arg.arg);
+  }
+
+  // Can't make this match DXC defaults
+  // DXC by default uses /O3 and FXC uses /O1
+
+  // Optimization flags are a special case.
+  // D3DCOMPILE_OPTIMIZATION_LEVEL0 = (1 << 14)
+  // D3DCOMPILE_OPTIMIZATION_LEVEL1 = 0
+  // D3DCOMPILE_OPTIMIZATION_LEVEL2 = ((1 << 14) | (1 << 15))
+  // D3DCOMPILE_OPTIMIZATION_LEVEL3 = (1 << 15)
+
+  uint32_t opt = (flags & D3DCOMPILE_OPTIMIZATION_LEVEL2);
+  if(opt == D3DCOMPILE_OPTIMIZATION_LEVEL0)
+    args.push_back(L"-O0");
+  else if(opt == D3DCOMPILE_OPTIMIZATION_LEVEL1)
+    args.push_back(L"-O1");
+  else if(opt == D3DCOMPILE_OPTIMIZATION_LEVEL2)
+    args.push_back(L"-O2");
+  else if(opt == D3DCOMPILE_OPTIMIZATION_LEVEL3)
+    args.push_back(L"-O3");
+};
+
 struct FxcArg
 {
   uint32_t bit;
diff --git a/renderdoc/driver/shaders/dxbc/dxbc_container.h b/renderdoc/driver/shaders/dxbc/dxbc_container.h
index 6fb7fa11a..0f1a47dd0 100644
--- a/renderdoc/driver/shaders/dxbc/dxbc_container.h
+++ b/renderdoc/driver/shaders/dxbc/dxbc_container.h
@@ -161,6 +161,7 @@ struct RDEFHeader;
 uint32_t DecodeFlags(const ShaderCompileFlags &compileFlags);
 rdcstr GetProfile(const ShaderCompileFlags &compileFlags);
 ShaderCompileFlags EncodeFlags(const uint32_t flags, const rdcstr &profile);
+void EncodeDXCFlags(uint32_t flags, rdcarray<rdcwstr> &args);
 
 // declare one of these and pass in your shader bytecode, then inspect
 // the members that are populated with the shader information.