diff --git a/test/Analysis/array-struct.c b/test/Analysis/array-struct.c
index 17c0d46..e602d5f 100644
--- a/test/Analysis/array-struct.c
+++ b/test/Analysis/array-struct.c
@@ -63,6 +63,8 @@
   char *p;
   p = __builtin_alloca(10); 
   p[1] = 'a';
+  // Test if RegionStore::EvalBinOp converts the alloca region to element
+  // region.
   p += 2;
 }