1 files changed, 1 insertions, 1 deletions
diff --git a/src/ir/analysis/derive_default.rs b/src/ir/analysis/derive_default.rs
index fe429e2a..4c2cad25 100644
--- a/src/ir/analysis/derive_default.rs
+++ b/src/ir/analysis/derive_default.rs
@@ -242,7 +242,7 @@ impl<'ctx, 'gen> MonotoneFramework for CannotDeriveDefault<'ctx, 'gen> {
                 );
 
                 if info.kind() == CompKind::Union {
-                    if self.ctx.options().unstable_rust {
+                    if self.ctx.options().rust_features().untagged_union() {
                         trace!("    cannot derive Default for Rust unions");
                         return self.insert(id);
                     }