diff --git a/compiler/rustc_infer/src/infer/at.rs b/compiler/rustc_infer/src/infer/at.rs
index 09313cd9738..e60e3ffeaa7 100644
--- a/compiler/rustc_infer/src/infer/at.rs
+++ b/compiler/rustc_infer/src/infer/at.rs
@@ -84,7 +84,7 @@ impl<'tcx> InferCtxt<'tcx> {
             selection_cache: self.selection_cache.clone(),
             evaluation_cache: self.evaluation_cache.clone(),
             reported_trait_errors: self.reported_trait_errors.clone(),
-            reported_closure_mismatch: self.reported_closure_mismatch.clone(),
+            reported_signature_mismatch: self.reported_signature_mismatch.clone(),
             tainted_by_errors: self.tainted_by_errors.clone(),
             err_count_on_creation: self.err_count_on_creation,
             universe: self.universe.clone(),
diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index fcc94687ed2..e164041c599 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/compiler/rustc_infer/src/infer/mod.rs
@@ -278,7 +278,7 @@ pub struct InferCtxt<'tcx> {
     /// avoid reporting the same error twice.
     pub reported_trait_errors: RefCell<FxIndexMap<Span, Vec<ty::Predicate<'tcx>>>>,
 
-    pub reported_closure_mismatch: RefCell<FxHashSet<(Span, Option<Span>)>>,
+    pub reported_signature_mismatch: RefCell<FxHashSet<(Span, Option<Span>)>>,
 
     /// When an error occurs, we want to avoid reporting "derived"
     /// errors that are due to this original failure. Normally, we
@@ -702,7 +702,7 @@ impl<'tcx> InferCtxtBuilder<'tcx> {
             selection_cache: Default::default(),
             evaluation_cache: Default::default(),
             reported_trait_errors: Default::default(),
-            reported_closure_mismatch: Default::default(),
+            reported_signature_mismatch: Default::default(),
             tainted_by_errors: Cell::new(None),
             err_count_on_creation: tcx.dcx().err_count(),
             universe: Cell::new(ty::UniverseIndex::ROOT),
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs
index 47a700805fa..a9fd538b6c0 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs
@@ -3459,14 +3459,12 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         let found_node = found_did.and_then(|did| self.tcx.hir().get_if_local(did));
         let found_span = found_did.and_then(|did| self.tcx.hir().span_if_local(did));
 
-        if self.reported_closure_mismatch.borrow().contains(&(span, found_span)) {
+        if !self.reported_signature_mismatch.borrow_mut().insert((span, found_span)) {
             // We check closures twice, with obligations flowing in different directions,
             // but we want to complain about them only once.
             return None;
         }
 
-        self.reported_closure_mismatch.borrow_mut().insert((span, found_span));
-
         let mut not_tupled = false;
 
         let found = match found_trait_ref.skip_binder().args.type_at(1).kind() {