diff --git a/clang/tools/driver/cc1as_main.cpp b/clang/tools/driver/cc1as_main.cpp
--- a/clang/tools/driver/cc1as_main.cpp
+++ b/clang/tools/driver/cc1as_main.cpp
@@ -170,6 +170,7 @@
     Dwarf64 = 0;
     DwarfVersion = 0;
     EmbedBitcode = 0;
+    EmitDwarfUnwind = EmitDwarfUnwindType::Default;
   }
 
   static bool CreateFromArgs(AssemblerInvocation &Res,