diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h
index 58eb1c0a7c114..e51ae9bfa37c3 100644
--- a/clang/include/clang/Parse/Parser.h
+++ b/clang/include/clang/Parse/Parser.h
@@ -2117,10 +2117,9 @@ class Parser : public CodeCompletionHandler {
 
   ExprResult ParseUnevaluatedStringInAttribute(const IdentifierInfo &AttrName);
 
-  bool
-  ParseAttributeArgumentList(const clang::IdentifierInfo &AttrName,
-                             SmallVectorImpl<Expr *> &Exprs,
-                             ParsedAttributeArgumentsProperties ArgsProperties);
+  bool parseAttributeArgumentList(
+      const IdentifierInfo &AttrName, SmallVectorImpl<Expr *> &Exprs,
+      ParsedAttributeArgumentsProperties ArgsProperties, unsigned Arg);
 
   /// Parses syntax-generic attribute arguments for attributes which are
   /// known to the implementation, and adds them to the given ParsedAttributes
diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index 8688ccf41acb5..26a1f7c0a5b93 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -421,11 +421,10 @@ Parser::ParseUnevaluatedStringInAttribute(const IdentifierInfo &AttrName) {
   return ParseUnevaluatedStringLiteralExpression();
 }
 
-bool Parser::ParseAttributeArgumentList(
+bool Parser::parseAttributeArgumentList(
     const IdentifierInfo &AttrName, SmallVectorImpl<Expr *> &Exprs,
-    ParsedAttributeArgumentsProperties ArgsProperties) {
+    ParsedAttributeArgumentsProperties ArgsProperties, unsigned Arg) {
   bool SawError = false;
-  unsigned Arg = 0;
   while (true) {
     ExprResult Expr;
     if (ArgsProperties.isStringLiteralArg(Arg)) {
@@ -580,7 +579,8 @@ unsigned Parser::ParseAttributeArgsCommon(
       ParsedAttributeArgumentsProperties ArgProperties =
           attributeStringLiteralListArg(getTargetInfo().getTriple(), *AttrName,
                                         Form.getSyntax(), ScopeName);
-      if (ParseAttributeArgumentList(*AttrName, ParsedExprs, ArgProperties)) {
+      if (parseAttributeArgumentList(*AttrName, ParsedExprs, ArgProperties,
+                                     ArgExprs.size())) {
         SkipUntil(tok::r_paren, StopAtSemi);
         return 0;
       }
diff --git a/clang/test/Sema/attr-modular-format.c b/clang/test/Sema/attr-modular-format.c
index fc5b28b0b88be..b7ae519cedbeb 100644
--- a/clang/test/Sema/attr-modular-format.c
+++ b/clang/test/Sema/attr-modular-format.c
@@ -3,6 +3,9 @@
 int printf(const char *fmt, ...)  __attribute__((modular_format(__modular_printf, "__printf", "float")));  // no-error
 int myprintf(const char *fmt, ...)  __attribute__((modular_format(__modular_printf, "__printf", "float")));  // expected-error {{'modular_format' attribute requires 'format' attribute}}
 
+int lprintf(const char *fmt, ...) __attribute__((modular_format(__modular_printf, L"__printf", L"float"), format(printf, 1, 2)));
+// expected-warning@-1 2{{encoding prefix 'L' on an unevaluated string literal has no effect}}
+
 int dupe(const char *fmt, ...)  __attribute__((modular_format(__modular_printf, "__printf", "float", "int", "float"), format(printf, 1, 2))); // expected-error {{duplicate aspect 'float' in 'modular_format' attribute}}
 int multi_dupe(const char *fmt, ...)  __attribute__((modular_format(__modular_printf, "__printf", "float", "int", "float", "int"), format(printf, 1, 2))); // expected-error {{duplicate aspect 'float' in 'modular_format' attribute}} \
                                                                                                                                                                  // expected-error {{duplicate aspect 'int' in 'modular_format' attribute}}