diff --git a/test/DebugInfo/X86/debug-dead-local-var.ll b/test/DebugInfo/X86/debug-dead-local-var.ll
index 798b6df6a81..64f0b2a9e40 100644
--- a/test/DebugInfo/X86/debug-dead-local-var.ll
+++ b/test/DebugInfo/X86/debug-dead-local-var.ll
@@ -1,6 +1,7 @@
 ; RUN: llc -mtriple=x86_64-linux-gnu %s -filetype=obj -o %t
 ; RUN: llvm-dwarfdump %t | FileCheck %s
 
+; Reconstruct this via clang and -O2.
 ; static void foo() {
 ;   struct X { int a; int b; } xyz;
 ; }