diff --git a/utils/llvm.grm b/utils/llvm.grm
index 86a707a925d..d391e2aeab9 100644
--- a/utils/llvm.grm
+++ b/utils/llvm.grm
@@ -162,6 +162,7 @@ FuncAttr      ::= noreturn
  | readnone
  | readonly
  | inlinehint
+ | alignstack
  | noinline
  | alwaysinline
  | optsize