diff --git a/src/parse/session.rs b/src/parse/session.rs
index 0573df9de2f..06f9c4c6243 100644
--- a/src/parse/session.rs
+++ b/src/parse/session.rs
@@ -284,10 +284,8 @@ pub(crate) fn get_original_snippet(&self, file_name: &FileName) -> Option<Lrc<St
 // Methods that should be restricted within the parse module.
 impl ParseSess {
     pub(super) fn emit_diagnostics(&self, diagnostics: Vec<Diagnostic>) {
-        for mut diagnostic in diagnostics {
-            self.parse_sess
-                .span_diagnostic
-                .emit_diagnostic(&mut diagnostic);
+        for diagnostic in diagnostics {
+            self.parse_sess.span_diagnostic.emit_diagnostic(diagnostic);
         }
     }