2 files changed, 5 insertions, 1 deletions
diff --git a/src/libsyntax_ext/format.rs b/src/libsyntax_ext/format.rs
index 2d296147a1f..e53660b6568 100644
--- a/src/libsyntax_ext/format.rs
+++ b/src/libsyntax_ext/format.rs
@@ -141,7 +141,10 @@ fn parse_args<'a>(
 
     while p.token != token::Eof {
         if !p.eat(&token::Comma) {
-            return Err(ecx.struct_span_err(p.token.span, "expected token: `,`"));
+            let mut err = ecx.struct_span_err(p.token.span, "expected token: `,`");
+            err.span_label(p.token.span, "expected `,`");
+            p.maybe_annotate_with_ascription(&mut err, false);
+            return Err(err);
         }
         if p.token == token::Eof {
             break;
diff --git a/src/libsyntax_ext/lib.rs b/src/libsyntax_ext/lib.rs
index da0f8ca6da0..7de90278ed7 100644
--- a/src/libsyntax_ext/lib.rs
+++ b/src/libsyntax_ext/lib.rs
@@ -12,6 +12,7 @@
 #![feature(decl_macro)]
 #![feature(nll)]
 #![feature(rustc_diagnostic_macros)]
+#![feature(unicode_internals)]
 
 #![recursion_limit="256"]