diff --git a/external/SPIRV-Headers b/external/SPIRV-Headers
index ae6a8b3971..1c9115b562 160000
--- a/external/SPIRV-Headers
+++ b/external/SPIRV-Headers
@@ -1 +1 @@
-Subproject commit ae6a8b39717523d96683bc0d20b541944e28072f
+Subproject commit 1c9115b562bab79ee2160fbd845f41b815b9f21f
diff --git a/external/SPIRV-Tools b/external/SPIRV-Tools
index 0045b01ff9..ad11927e6c 160000
--- a/external/SPIRV-Tools
+++ b/external/SPIRV-Tools
@@ -1 +1 @@
-Subproject commit 0045b01ff9648eeef1781282f0454ae584f3ace7
+Subproject commit ad11927e6cb251624f884327ede64a642be11f06
diff --git a/tools/clang/test/CodeGenSPIRV/meshshading.ext.optimized.hlsl b/tools/clang/test/CodeGenSPIRV/meshshading.ext.optimized.hlsl
new file mode 100644
index 0000000000..3315ce5381
--- /dev/null
+++ b/tools/clang/test/CodeGenSPIRV/meshshading.ext.optimized.hlsl
@@ -0,0 +1,23 @@
+// RUN: %dxc -T ms_6_6 -E main -spirv -fspv-target-env=vulkan1.3 %s | FileCheck %s
+
+// CHECK:      OpExtension "SPV_EXT_mesh_shader"
+
+struct Object
+{
+    float4 v: SV_POSITION;
+};
+
+RWStructuredBuffer<int> buffer;
+
+// If optimizations are disabled, this function is not inlined.
+// This means a RWStructuredBuffer will be created as a local variable,
+// which is impossible in logical SPIR-V.
+// Hence why should make sure the optimizations are enabled for mesh shaders.
+void foo(RWStructuredBuffer<int> param) { }
+
+[outputtopology("triangle")]
+[numthreads(1, 1, 1)]
+void main(out indices uint3 idx[3], out vertices Object vtx[3])
+{
+  foo(buffer);
+}