diff --git a/test/M3/RootSignatures/Defaults.test b/test/M3/RootSignatures/Defaults.test
new file mode 100644
index 000000000..ac3463605
--- /dev/null
+++ b/test/M3/RootSignatures/Defaults.test
@@ -0,0 +1,94 @@
+#--- source.hlsl
+
+cbuffer RootConstants : register(b0) {
+ float4 C;
+};
+
+struct Input {
+ float4 A;
+ float4 B;
+};
+
+struct Output {
+ float4 A;
+};
+
+StructuredBuffer In : register(t0);
+RWStructuredBuffer