diff --git a/src/monomorphize_collector.rs b/src/monomorphize_collector.rs
index 6bd29e2..8c59228 100644
--- a/src/monomorphize_collector.rs
+++ b/src/monomorphize_collector.rs
@@ -856,7 +856,7 @@ pub fn find_vtable_types_for_unsizing<'tcx>(
 ) -> (Ty<'tcx>, Ty<'tcx>) {
     let ptr_vtable = |inner_source: Ty<'tcx>, inner_target: Ty<'tcx>| {
         let type_has_metadata = |ty: Ty<'tcx>| -> bool {
-            if ty.is_sized(tcx.tcx, typing_env.param_env) {
+            if ty.is_sized(tcx.tcx, typing_env) {
                 return false;
             }
             let tail = tcx.struct_tail_for_codegen(ty, typing_env);