diff --git a/src/librustc_infer/traits/auto_trait.rs b/src/librustc_infer/traits/auto_trait.rs
index 1a4f899ac859..3166fe065769 100644
--- a/src/librustc_infer/traits/auto_trait.rs
+++ b/src/librustc_infer/traits/auto_trait.rs
@@ -150,7 +150,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
             // SelectionContext to return it back to us.
 
             let (new_env, user_env) = match self.evaluate_predicates(
-                &mut infcx,
+                &infcx,
                 trait_did,
                 ty,
                 orig_env,
diff --git a/src/librustc_mir/dataflow/generic/visitor.rs b/src/librustc_mir/dataflow/generic/visitor.rs
index 5bad8c61a0cd..6e1513bcd1dd 100644
--- a/src/librustc_mir/dataflow/generic/visitor.rs
+++ b/src/librustc_mir/dataflow/generic/visitor.rs
@@ -22,20 +22,20 @@ pub fn visit_results<F>(
             let loc = Location { block, statement_index };
 
             results.reconstruct_before_statement_effect(&mut state, stmt, loc);
-            vis.visit_statement(&mut state, stmt, loc);
+            vis.visit_statement(&state, stmt, loc);
 
             results.reconstruct_statement_effect(&mut state, stmt, loc);
-            vis.visit_statement_exit(&mut state, stmt, loc);
+            vis.visit_statement_exit(&state, stmt, loc);
         }
 
         let loc = body.terminator_loc(block);
         let term = block_data.terminator();
 
         results.reconstruct_before_terminator_effect(&mut state, term, loc);
-        vis.visit_terminator(&mut state, term, loc);
+        vis.visit_terminator(&state, term, loc);
 
         results.reconstruct_terminator_effect(&mut state, term, loc);
-        vis.visit_terminator_exit(&mut state, term, loc);
+        vis.visit_terminator_exit(&state, term, loc);
     }
 }
 
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index b7353c6af267..d8b23998e727 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -737,8 +737,8 @@ impl ItemLikeVisitor<'tcx> for CheckItemTypesVisitor<'tcx> {
 }
 
 pub fn check_wf_new(tcx: TyCtxt<'_>) {
-    let mut visit = wfcheck::CheckTypeWellFormedVisitor::new(tcx);
-    tcx.hir().krate().par_visit_all_item_likes(&mut visit);
+    let visit = wfcheck::CheckTypeWellFormedVisitor::new(tcx);
+    tcx.hir().krate().par_visit_all_item_likes(&visit);
 }
 
 fn check_mod_item_types(tcx: TyCtxt<'_>, module_def_id: DefId) {