diff --git a/clippy_lints/src/doc.rs b/clippy_lints/src/doc.rs
index 4557e432885..ae5f9424b23 100644
--- a/clippy_lints/src/doc.rs
+++ b/clippy_lints/src/doc.rs
@@ -427,9 +427,7 @@ fn lint_for_missing_headers(
                 let body = cx.tcx.hir().body(body_id);
                 let ret_ty = typeck.expr_ty(body.value);
                 if implements_trait(cx, ret_ty, future, &[]);
-                if let ty::Opaque(_, subs) = ret_ty.kind();
-                if let Some(gen) = subs.types().next();
-                if let ty::Generator(_, subs, _) = gen.kind();
+                if let ty::Generator(_, subs, _) = ret_ty.kind();
                 if is_type_diagnostic_item(cx, subs.as_generator().return_ty(), sym::Result);
                 then {
                     span_lint(
diff --git a/clippy_lints/src/manual_async_fn.rs b/clippy_lints/src/manual_async_fn.rs
index 5c6a342b3d0..6a98df49912 100644
--- a/clippy_lints/src/manual_async_fn.rs
+++ b/clippy_lints/src/manual_async_fn.rs
@@ -177,7 +177,7 @@ fn desugared_async_block<'tcx>(cx: &LateContext<'tcx>, block: &'tcx Block<'tcx>)
         if let Some(args) = cx
             .tcx
             .lang_items()
-            .from_generator_fn()
+            .identity_future_fn()
             .and_then(|def_id| match_function_call_with_def_id(cx, block_expr, def_id));
         if args.len() == 1;
         if let Expr {
diff --git a/tests/ui/author/blocks.stdout b/tests/ui/author/blocks.stdout
index 9de0550d81d..c6acf24c21e 100644
--- a/tests/ui/author/blocks.stdout
+++ b/tests/ui/author/blocks.stdout
@@ -45,7 +45,7 @@ if let ExprKind::Closure(CaptureBy::Value, fn_decl, body_id, _, None) = expr.kin
     && expr1 = &cx.tcx.hir().body(body_id).value
     && let ExprKind::Call(func, args) = expr1.kind
     && let ExprKind::Path(ref qpath) = func.kind
-    && matches!(qpath, QPath::LangItem(LangItem::FromGenerator, _))
+    && matches!(qpath, QPath::LangItem(LangItem::IdentityFuture, _))
     && args.len() == 1
     && let ExprKind::Closure(CaptureBy::Value, fn_decl1, body_id1, _, Some(Movability::Static)) = args[0].kind
     && let FnRetTy::DefaultReturn(_) = fn_decl1.output