diff --git a/tests/foo/1.0/IFoo.hal b/tests/foo/1.0/IFoo.hal
index a073e54fb5..d0119ec3a0 100644
--- a/tests/foo/1.0/IFoo.hal
+++ b/tests/foo/1.0/IFoo.hal
@@ -95,4 +95,6 @@ interface IFoo {
 
     transpose(StringMatrix5x3 in) generates (StringMatrix3x5 out);
     transpose2(ThreeStrings[5] in) generates (FiveStrings[3] out);
+
+    sendVec(vec<uint8_t> data) generates (vec<uint8_t> data);
 };