diff --git a/include/llvm/Support/CommandLine.h b/include/llvm/Support/CommandLine.h
index c5e909d8a26..9cad99f4415 100644
--- a/include/llvm/Support/CommandLine.h
+++ b/include/llvm/Support/CommandLine.h
@@ -894,7 +894,8 @@ class list : public Option, public list_storage<DataType, Storage> {
 
   virtual bool handleOccurrence(unsigned pos, const char *ArgName,
                                 const std::string &Arg) {
-    typename ParserClass::parser_data_type Val;
+    typename ParserClass::parser_data_type Val =
+      typename ParserClass::parser_data_type();
     if (Parser.parse(*this, ArgName, Arg, Val))
       return true;  // Parse Error!
     addValue(Val);