diff --git a/src/librustc/hir/lowering.rs b/src/librustc/hir/lowering.rs
index 62bedcdfcbe61..873d39ec9e9fb 100644
--- a/src/librustc/hir/lowering.rs
+++ b/src/librustc/hir/lowering.rs
@@ -2170,12 +2170,12 @@ impl<'a> LoweringContext<'a> {
// let result = match ::std::iter::IntoIterator::into_iter(
) {
// mut iter => {
// [opt_ident]: loop {
- // let mut _next;
+ // let mut __next;
// match ::std::iter::Iterator::next(&mut iter) {
- // ::std::option::Option::Some(val) => _next = val,
+ // ::std::option::Option::Some(val) => __next = val,
// ::std::option::Option::None => break
// };
- // let = _next;
+ // let = __next;
// StmtExpr();
// }
// }
@@ -2188,7 +2188,7 @@ impl<'a> LoweringContext<'a> {
let iter = self.str_to_ident("iter");
- let next_ident = self.str_to_ident("_next");
+ let next_ident = self.str_to_ident("__next");
let next_pat = self.pat_ident_binding_mode(e.span,
next_ident,
hir::BindByValue(hir::MutMutable));
@@ -2237,13 +2237,13 @@ impl<'a> LoweringContext<'a> {
let next_expr = P(self.expr_ident(e.span, next_ident, next_pat.id));
- // `let mut _next`
+ // `let mut __next`
let next_let = self.stmt_let_pat(e.span,
None,
next_pat,
hir::LocalSource::ForLoopDesugar);
- // `let = _next`
+ // `let = __next`
let pat = self.lower_pat(pat);
let pat_let = self.stmt_let_pat(e.span,
Some(next_expr),