1 files changed, 26 insertions, 0 deletions
diff --git a/tests/autodiff/custom-differential-type-error.slang b/tests/autodiff/custom-differential-type-error.slang
new file mode 100644
index 000000000..2542eff4f
--- /dev/null
+++ b/tests/autodiff/custom-differential-type-error.slang
@@ -0,0 +1,26 @@
+//TEST:SIMPLE(filecheck=CHECK):-target spirv
+
+interface IFoo : IDifferentiable
+{
+    float myFunc();
+}
+
+struct Bar: IDifferentiable
+{
+    float y;
+}
+
+struct Foo :  IFoo
+{
+    typealias Differential = Bar;
+
+    // CHECK: ([[# @LINE+1]]): error 30027: 'x' is not a member of 'typeof(Foo.Differential)'.
+    [DerivativeMember(Differential.x)]
+    float x;
+
+    [BackwardDifferentiable]
+    float myFunc()
+    {
+        return x * x;
+    };
+}