diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
index ace5e34b38249..fa061c806180f 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
@@ -1520,7 +1520,7 @@ fn generics_args_err_extend<'a>(
                 })
                 .collect();
             if args.len() > 1
-                && let Some(span) = args.into_iter().last()
+                && let Some(span) = args.into_iter().next_back()
             {
                 err.note(
                     "generic arguments are not allowed on both an enum and its variant's path \
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs
index bb227a58cf19d..716ababb00802 100644
--- a/compiler/rustc_parse/src/parser/diagnostics.rs
+++ b/compiler/rustc_parse/src/parser/diagnostics.rs
@@ -2107,7 +2107,7 @@ impl<'a> Parser<'a> {
                     ast::GenericBound::Trait(poly) => Some(poly),
                     _ => None,
                 })
-                .last()
+                .next_back()
         {
             err.span_suggestion_verbose(
                 poly.span.shrink_to_hi(),