diff --git a/compiler/rustc_ast_lowering/src/errors.rs b/compiler/rustc_ast_lowering/src/errors.rs
index ca0821e2c9e..6799513a323 100644
--- a/compiler/rustc_ast_lowering/src/errors.rs
+++ b/compiler/rustc_ast_lowering/src/errors.rs
@@ -44,7 +44,7 @@ impl Subdiagnostic for InvalidAbiReason {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _: F,
+        _: &F,
     ) {
         #[allow(rustc::untranslatable_diagnostic)]
         diag.note(self.0);
diff --git a/compiler/rustc_ast_passes/src/errors.rs b/compiler/rustc_ast_passes/src/errors.rs
index f397c949e04..25a125f8393 100644
--- a/compiler/rustc_ast_passes/src/errors.rs
+++ b/compiler/rustc_ast_passes/src/errors.rs
@@ -382,7 +382,7 @@ impl Subdiagnostic for EmptyLabelManySpans {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _: F,
+        _: &F,
     ) {
         diag.span_labels(self.0, "");
     }
@@ -751,7 +751,7 @@ impl Subdiagnostic for StableFeature {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _: F,
+        _: &F,
     ) {
         diag.arg("name", self.name);
         diag.arg("since", self.since);
diff --git a/compiler/rustc_builtin_macros/src/errors.rs b/compiler/rustc_builtin_macros/src/errors.rs
index 6b6647ef085..9078dc07a31 100644
--- a/compiler/rustc_builtin_macros/src/errors.rs
+++ b/compiler/rustc_builtin_macros/src/errors.rs
@@ -601,7 +601,7 @@ impl Subdiagnostic for FormatUnusedArg {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        f: F,
+        f: &F,
     ) {
         diag.arg("named", self.named);
         let msg = f(diag, crate::fluent_generated::builtin_macros_format_unused_arg.into());
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index a17e0da47a5..6c84eeaf888 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -177,7 +177,7 @@ where
 {
     /// Add a subdiagnostic to an existing diagnostic.
     fn add_to_diag<G: EmissionGuarantee>(self, diag: &mut Diag<'_, G>) {
-        self.add_to_diag_with(diag, |_, m| m);
+        self.add_to_diag_with(diag, &|_, m| m);
     }
 
     /// Add a subdiagnostic to an existing diagnostic where `f` is invoked on every message used
@@ -185,7 +185,7 @@ where
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        f: F,
+        f: &F,
     );
 }
 
@@ -1197,7 +1197,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
         dcx: &crate::DiagCtxt,
         subdiagnostic: impl Subdiagnostic,
     ) -> &mut Self {
-        subdiagnostic.add_to_diag_with(self, |diag, msg| {
+        subdiagnostic.add_to_diag_with(self, &|diag, msg| {
             let args = diag.args.iter();
             let msg = diag.subdiagnostic_message_to_diagnostic_message(msg);
             dcx.eagerly_translate(msg, args)
diff --git a/compiler/rustc_errors/src/diagnostic_impls.rs b/compiler/rustc_errors/src/diagnostic_impls.rs
index 6c0551848d6..1ef945985be 100644
--- a/compiler/rustc_errors/src/diagnostic_impls.rs
+++ b/compiler/rustc_errors/src/diagnostic_impls.rs
@@ -302,7 +302,7 @@ impl Subdiagnostic for SingleLabelManySpans {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _: F,
+        _: &F,
     ) {
         diag.span_labels(self.spans, self.label);
     }
diff --git a/compiler/rustc_hir_typeck/src/errors.rs b/compiler/rustc_hir_typeck/src/errors.rs
index 3dc9c7b86f7..1c4d5657b17 100644
--- a/compiler/rustc_hir_typeck/src/errors.rs
+++ b/compiler/rustc_hir_typeck/src/errors.rs
@@ -191,7 +191,7 @@ impl Subdiagnostic for TypeMismatchFruTypo {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         diag.arg("expr", self.expr.as_deref().unwrap_or("NONE"));
 
@@ -370,7 +370,7 @@ impl Subdiagnostic for RemoveSemiForCoerce {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         let mut multispan: MultiSpan = self.semi.into();
         multispan.push_span_label(self.expr, fluent::hir_typeck_remove_semi_for_coerce_expr);
@@ -546,7 +546,7 @@ impl rustc_errors::Subdiagnostic for CastUnknownPointerSub {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        f: F,
+        f: &F,
     ) {
         match self {
             CastUnknownPointerSub::To(span) => {
diff --git a/compiler/rustc_infer/src/errors/mod.rs b/compiler/rustc_infer/src/errors/mod.rs
index 4593108edac..2acaeac2439 100644
--- a/compiler/rustc_infer/src/errors/mod.rs
+++ b/compiler/rustc_infer/src/errors/mod.rs
@@ -239,7 +239,7 @@ impl Subdiagnostic for RegionOriginNote<'_> {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         let mut label_or_note = |span, msg: DiagMessage| {
             let sub_count = diag.children.iter().filter(|d| d.span.is_dummy()).count();
@@ -304,7 +304,7 @@ impl Subdiagnostic for LifetimeMismatchLabels {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         match self {
             LifetimeMismatchLabels::InRet { param_span, ret_span, span, label_var1 } => {
@@ -352,7 +352,7 @@ impl Subdiagnostic for AddLifetimeParamsSuggestion<'_> {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         let mut mk_suggestion = || {
             let (
@@ -454,7 +454,7 @@ impl Subdiagnostic for IntroducesStaticBecauseUnmetLifetimeReq {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         mut self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         self.unmet_requirements
             .push_span_label(self.binding_span, fluent::infer_msl_introduces_static);
@@ -773,7 +773,7 @@ impl Subdiagnostic for ConsiderBorrowingParamHelp {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        f: F,
+        f: &F,
     ) {
         let mut type_param_span: MultiSpan = self.spans.clone().into();
         for &span in &self.spans {
@@ -818,7 +818,7 @@ impl Subdiagnostic for DynTraitConstraintSuggestion {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        f: F,
+        f: &F,
     ) {
         let mut multi_span: MultiSpan = vec![self.span].into();
         multi_span.push_span_label(self.span, fluent::infer_dtcs_has_lifetime_req_label);
@@ -865,7 +865,7 @@ impl Subdiagnostic for ReqIntroducedLocations {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         mut self,
         diag: &mut Diag<'_, G>,
-        f: F,
+        f: &F,
     ) {
         for sp in self.spans {
             self.span.push_span_label(sp, fluent::infer_ril_introduced_here);
@@ -888,7 +888,7 @@ impl Subdiagnostic for MoreTargeted {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         diag.code(E0772);
         diag.primary_message(fluent::infer_more_targeted);
@@ -1293,7 +1293,7 @@ impl Subdiagnostic for SuggestTuplePatternMany {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        f: F,
+        f: &F,
     ) {
         diag.arg("path", self.path);
         let message = f(diag, crate::fluent_generated::infer_stp_wrap_many.into());
diff --git a/compiler/rustc_infer/src/errors/note_and_explain.rs b/compiler/rustc_infer/src/errors/note_and_explain.rs
index 7b962b01408..70d94873530 100644
--- a/compiler/rustc_infer/src/errors/note_and_explain.rs
+++ b/compiler/rustc_infer/src/errors/note_and_explain.rs
@@ -163,7 +163,7 @@ impl Subdiagnostic for RegionExplanation<'_> {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        f: F,
+        f: &F,
     ) {
         diag.arg("pref_kind", self.prefix);
         diag.arg("suff_kind", self.suffix);
diff --git a/compiler/rustc_lint/src/errors.rs b/compiler/rustc_lint/src/errors.rs
index ee99e824a54..c23d1221bc8 100644
--- a/compiler/rustc_lint/src/errors.rs
+++ b/compiler/rustc_lint/src/errors.rs
@@ -27,7 +27,7 @@ impl Subdiagnostic for OverruledAttributeSub {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         match self {
             OverruledAttributeSub::DefaultSource { id } => {
diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs
index a034bebc85e..74a0a224dba 100644
--- a/compiler/rustc_lint/src/lints.rs
+++ b/compiler/rustc_lint/src/lints.rs
@@ -274,7 +274,7 @@ impl<'a, 'b> Subdiagnostic for SuggestChangingAssocTypes<'a, 'b> {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         // Access to associates types should use `<T as Bound>::Assoc`, which does not need a
         // bound. Let's see if this type does that.
@@ -330,7 +330,7 @@ impl Subdiagnostic for BuiltinTypeAliasGenericBoundsSuggestion {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         diag.multipart_suggestion(
             fluent::lint_suggestion,
@@ -451,7 +451,7 @@ impl Subdiagnostic for BuiltinUnpermittedTypeInitSub {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         let mut err = self.err;
         loop {
@@ -506,7 +506,7 @@ impl Subdiagnostic for BuiltinClashingExternSub<'_> {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         let mut expected_str = DiagStyledString::new();
         expected_str.push(self.expected.fn_sig(self.tcx).to_string(), false);
@@ -788,7 +788,7 @@ impl Subdiagnostic for HiddenUnicodeCodepointsDiagLabels {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         for (c, span) in self.spans {
             diag.span_label(span, format!("{c:?}"));
@@ -806,7 +806,7 @@ impl Subdiagnostic for HiddenUnicodeCodepointsDiagSub {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         match self {
             HiddenUnicodeCodepointsDiagSub::Escape { spans } => {
@@ -954,7 +954,7 @@ impl Subdiagnostic for NonBindingLetSub {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         let can_suggest_binding = self.drop_fn_start_end.is_some() || !self.is_assign_desugar;
 
@@ -1240,7 +1240,7 @@ impl Subdiagnostic for NonSnakeCaseDiagSub {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         match self {
             NonSnakeCaseDiagSub::Label { span } => {
@@ -1482,7 +1482,7 @@ impl Subdiagnostic for OverflowingBinHexSign {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         match self {
             OverflowingBinHexSign::Positive => {
diff --git a/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs b/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs
index ced782cdbc0..94914266884 100644
--- a/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs
+++ b/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs
@@ -90,7 +90,7 @@ impl SubdiagnosticDerive {
                 fn add_to_diag_with<__G, __F>(
                     self,
                     #diag: &mut rustc_errors::Diag<'_, __G>,
-                    #f: __F
+                    #f: &__F
                 ) where
                     __G: rustc_errors::EmissionGuarantee,
                     __F: rustc_errors::SubdiagMessageOp<__G>,
diff --git a/compiler/rustc_mir_build/src/errors.rs b/compiler/rustc_mir_build/src/errors.rs
index 9ddfb12bf76..f67113afd6d 100644
--- a/compiler/rustc_mir_build/src/errors.rs
+++ b/compiler/rustc_mir_build/src/errors.rs
@@ -423,7 +423,7 @@ impl Subdiagnostic for UnsafeNotInheritedLintNote {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         diag.span_note(self.signature_span, fluent::mir_build_unsafe_fn_safe_body);
         let body_start = self.body_span.shrink_to_lo();
@@ -871,7 +871,7 @@ impl<'tcx> Subdiagnostic for AdtDefinedHere<'tcx> {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         diag.arg("ty", self.ty);
         let mut spans = MultiSpan::from(self.adt_def_span);
diff --git a/compiler/rustc_parse/src/errors.rs b/compiler/rustc_parse/src/errors.rs
index eae2d904c35..a5d18a919c4 100644
--- a/compiler/rustc_parse/src/errors.rs
+++ b/compiler/rustc_parse/src/errors.rs
@@ -1463,7 +1463,7 @@ impl Subdiagnostic for FnTraitMissingParen {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _: F,
+        _: &F,
     ) {
         diag.span_label(self.span, crate::fluent_generated::parse_fn_trait_missing_paren);
         let applicability = if self.machine_applicable {
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index 3f26ea4507d..27e0ddc64d9 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -1755,7 +1755,7 @@ impl Subdiagnostic for UnusedVariableStringInterp {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         diag.span_label(self.lit, crate::fluent_generated::passes_maybe_string_interpolation);
         diag.multipart_suggestion(
diff --git a/compiler/rustc_pattern_analysis/src/errors.rs b/compiler/rustc_pattern_analysis/src/errors.rs
index 75b7b7c8f67..27f227e6d9c 100644
--- a/compiler/rustc_pattern_analysis/src/errors.rs
+++ b/compiler/rustc_pattern_analysis/src/errors.rs
@@ -65,7 +65,7 @@ impl<'tcx> Subdiagnostic for Overlap<'tcx> {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _: F,
+        _: &F,
     ) {
         let Overlap { span, range } = self;
 
@@ -113,7 +113,7 @@ impl<'tcx> Subdiagnostic for GappedRange<'tcx> {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _: F,
+        _: &F,
     ) {
         let GappedRange { span, gap, first_range } = self;
 
diff --git a/compiler/rustc_trait_selection/src/errors.rs b/compiler/rustc_trait_selection/src/errors.rs
index b126062102e..9b08a86ef16 100644
--- a/compiler/rustc_trait_selection/src/errors.rs
+++ b/compiler/rustc_trait_selection/src/errors.rs
@@ -104,7 +104,7 @@ impl Subdiagnostic for AdjustSignatureBorrow {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        _f: F,
+        _f: &F,
     ) {
         match self {
             AdjustSignatureBorrow::Borrow { to_borrow } => {
diff --git a/tests/ui-fulldeps/internal-lints/diagnostics.rs b/tests/ui-fulldeps/internal-lints/diagnostics.rs
index 1d7417be58c..380b2b6c431 100644
--- a/tests/ui-fulldeps/internal-lints/diagnostics.rs
+++ b/tests/ui-fulldeps/internal-lints/diagnostics.rs
@@ -59,7 +59,7 @@ impl Subdiagnostic for UntranslatableInAddtoDiag {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        f: F,
+        f: &F,
     ) {
         diag.note("untranslatable diagnostic");
         //~^ ERROR diagnostics should be created using translatable messages
@@ -72,7 +72,7 @@ impl Subdiagnostic for TranslatableInAddtoDiag {
     fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
-        f: F,
+        f: &F,
     ) {
         diag.note(crate::fluent_generated::no_crate_note);
     }