diff --git a/compiler/rustc_symbol_mangling/src/errors.rs b/compiler/rustc_symbol_mangling/src/errors.rs
index db8b3159a6ff..c0e49e07bfc5 100644
--- a/compiler/rustc_symbol_mangling/src/errors.rs
+++ b/compiler/rustc_symbol_mangling/src/errors.rs
@@ -5,24 +5,24 @@ use rustc_span::Span;
 
 #[derive(SessionDiagnostic)]
 #[error(symbol_mangling::invalid_symbol_name)]
-pub struct InvalidSymbolName<'a> {
+pub struct InvalidSymbolName {
     #[primary_span]
     pub span: Span,
-    pub mangled_formatted: &'a str,
+    pub mangled_formatted: String,
 }
 
 #[derive(SessionDiagnostic)]
 #[error(symbol_mangling::invalid_trait_item)]
-pub struct InvalidTraitItem<'a> {
+pub struct InvalidTraitItem {
     #[primary_span]
     pub span: Span,
-    pub demangling_formatted: &'a str,
+    pub demangling_formatted: String,
 }
 
 #[derive(SessionDiagnostic)]
 #[error(symbol_mangling::alt_invalid_trait_item)]
-pub struct AltInvalidTraitItem<'a> {
+pub struct AltInvalidTraitItem {
     #[primary_span]
     pub span: Span,
-    pub alt_demangling_formatted: &'a str,
+    pub alt_demangling_formatted: String,
 }
diff --git a/compiler/rustc_symbol_mangling/src/test.rs b/compiler/rustc_symbol_mangling/src/test.rs
index 06efefb726ca..2ed1dea357dd 100644
--- a/compiler/rustc_symbol_mangling/src/test.rs
+++ b/compiler/rustc_symbol_mangling/src/test.rs
@@ -62,16 +62,16 @@ impl SymbolNamesTest<'_> {
             let mangled = tcx.symbol_name(instance);
             tcx.sess.emit_err(InvalidSymbolName {
                 span: attr.span,
-                mangled_formatted: &format!("{mangled}"),
+                mangled_formatted: format!("{mangled}"),
             });
             if let Ok(demangling) = rustc_demangle::try_demangle(mangled.name) {
                 tcx.sess.emit_err(InvalidTraitItem {
                     span: attr.span,
-                    demangling_formatted: &format!("{demangling}"),
+                    demangling_formatted: format!("{demangling}"),
                 });
                 tcx.sess.emit_err(AltInvalidTraitItem {
                     span: attr.span,
-                    alt_demangling_formatted: &format!("{:#}", demangling),
+                    alt_demangling_formatted: format!("{:#}", demangling),
                 });
             }
         }