diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
index d3a231489653c..2cb498822ce35 100644
--- a/clang/lib/Parse/ParseExpr.cpp
+++ b/clang/lib/Parse/ParseExpr.cpp
@@ -1419,6 +1419,7 @@ ExprResult Parser::ParseCastExpression(CastParseKind ParseKind,
         Diag(Tok, diag::err_amp_illegal_keyword_dynamiccast);
       }
     }
+    LLVM_FALLTHROUGH;
   case tok::kw_const_cast:
   case tok::kw_reinterpret_cast:
   case tok::kw_static_cast: