1 files changed, 4 insertions, 0 deletions
diff --git a/src/libsyntax/parse/parser/generics.rs b/src/libsyntax/parse/parser/generics.rs
index bfcb0042a75..51caae69c86 100644
--- a/src/libsyntax/parse/parser/generics.rs
+++ b/src/libsyntax/parse/parser/generics.rs
@@ -55,11 +55,15 @@ impl<'a> Parser<'a> {
     }
 
     fn parse_const_param(&mut self, preceding_attrs: Vec<Attribute>) -> PResult<'a, GenericParam> {
+        let lo = self.token.span;
+
         self.expect_keyword(kw::Const)?;
         let ident = self.parse_ident()?;
         self.expect(&token::Colon)?;
         let ty = self.parse_ty()?;
 
+        self.sess.gated_spans.const_generics.borrow_mut().push(lo.to(self.prev_span));
+
         Ok(GenericParam {
             ident,
             id: ast::DUMMY_NODE_ID,