2 files changed, 4 insertions, 0 deletions
diff --git a/compiler/rustc_session/src/lib.rs b/compiler/rustc_session/src/lib.rs
index 14273b07ebd..3151b025fff 100644
--- a/compiler/rustc_session/src/lib.rs
+++ b/compiler/rustc_session/src/lib.rs
@@ -1,5 +1,6 @@
 #![feature(crate_visibility_modifier)]
 #![feature(derive_default_enum)]
+#![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(let_else)]
 #![feature(min_specialization)]
diff --git a/compiler/rustc_session/src/utils.rs b/compiler/rustc_session/src/utils.rs
index 6a8775bd10b..9a286d94ab8 100644
--- a/compiler/rustc_session/src/utils.rs
+++ b/compiler/rustc_session/src/utils.rs
@@ -132,6 +132,9 @@ impl<'a> FlattenNonterminals<'a> {
 
     pub fn process_token(&mut self, token: Token) -> TokenStream {
         match token.kind {
+            token::Interpolated(nt) if let token::NtIdent(ident, is_raw) = *nt => {
+                TokenTree::Token(Token::new(token::Ident(ident.name, is_raw), ident.span)).into()
+            }
             token::Interpolated(nt) => {
                 let tts = (self.nt_to_tokenstream)(&nt, self.parse_sess, self.synthesize_tokens);
                 TokenTree::Delimited(