diff --git a/src/librustdoc/html/render/context.rs b/src/librustdoc/html/render/context.rs
index db718fbe6738..f7bfd7add292 100644
--- a/src/librustdoc/html/render/context.rs
+++ b/src/librustdoc/html/render/context.rs
@@ -56,7 +56,7 @@ crate struct Context<'tcx> {
     pub(super) render_redirect_pages: bool,
     /// Tracks section IDs for `Deref` targets so they match in both the main
     /// body and the sidebar.
-    pub(super) deref_id_map: Rc<RefCell<FxHashMap<DefId, String>>>,
+    pub(super) deref_id_map: RefCell<FxHashMap<DefId, String>>,
     /// The map used to ensure all generated 'id=' attributes are unique.
     pub(super) id_map: RefCell<IdMap>,
     /// Shared mutable state.
@@ -73,7 +73,7 @@ crate struct Context<'tcx> {
 
 // `Context` is cloned a lot, so we don't want the size to grow unexpectedly.
 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
-rustc_data_structures::static_assert_size!(Context<'_>, 112);
+rustc_data_structures::static_assert_size!(Context<'_>, 144);
 
 /// Shared mutable state used in [`Context`] and elsewhere.
 crate struct SharedContext<'tcx> {
@@ -516,7 +516,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             dst,
             render_redirect_pages: false,
             id_map: RefCell::new(id_map),
-            deref_id_map: Rc::new(RefCell::new(FxHashMap::default())),
+            deref_id_map: RefCell::new(FxHashMap::default()),
             shared: Rc::new(scx),
             include_sources,
         };
@@ -540,7 +540,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             current: self.current.clone(),
             dst: self.dst.clone(),
             render_redirect_pages: self.render_redirect_pages,
-            deref_id_map: Rc::new(RefCell::new(FxHashMap::default())),
+            deref_id_map: RefCell::new(FxHashMap::default()),
             id_map: RefCell::new(IdMap::new()),
             shared: Rc::clone(&self.shared),
             include_sources: self.include_sources,