diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index 2a39e19..777ce3a 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -664,6 +664,7 @@
   KEYWORD(noreturn);
   KEYWORD(nosync);
   KEYWORD(nocf_check);
+  KEYWORD(noundef);
   KEYWORD(nounwind);
   KEYWORD(null_pointer_is_valid);
   KEYWORD(optforfuzzing);