diff --git a/src/parse/session.rs b/src/parse/session.rs
index 11af9860513..cf8120e9b09 100644
--- a/src/parse/session.rs
+++ b/src/parse/session.rs
@@ -383,6 +383,7 @@ mod tests {
         }
 
         fn build_diagnostic(level: DiagnosticLevel, span: Option<MultiSpan>) -> DiagInner {
+            #[allow(rustc::untranslatable_diagnostic)] // no translation needed for empty string
             let mut diag = DiagInner::new(level, "");
             diag.messages.clear();
             if let Some(span) = span {