diff --git a/src/test/ui/issues/issue-23458.rs b/src/test/ui/issues/issue-23458.rs
index 423b19c3ebd09..1762d21832848 100644
--- a/src/test/ui/issues/issue-23458.rs
+++ b/src/test/ui/issues/issue-23458.rs
@@ -1,5 +1,5 @@
 #![feature(llvm_asm)]
-
+// compile-flags: -Ccodegen-units=1
 // build-fail
 // only-x86_64