diff --git a/src/test/ui/align-with-extern-c-fn.rs b/src/test/ui/align-with-extern-c-fn.rs
index b336ed76940c..8ba90225c6c7 100644
--- a/src/test/ui/align-with-extern-c-fn.rs
+++ b/src/test/ui/align-with-extern-c-fn.rs
@@ -7,10 +7,9 @@
 
 #![feature(repr_align)]
 
-#[repr(align(16))]
+#[repr(align(16), C)]
 pub struct A(i64);
 
-#[allow(improper_ctypes)]
 pub extern "C" fn foo(x: A) {}
 
 fn main() {