diff --git a/compiler/rustc_mir_build/src/thir/cx/expr.rs b/compiler/rustc_mir_build/src/thir/cx/expr.rs
index 02deff647408..8cc5cda59ab0 100644
--- a/compiler/rustc_mir_build/src/thir/cx/expr.rs
+++ b/compiler/rustc_mir_build/src/thir/cx/expr.rs
@@ -806,6 +806,10 @@ fn make_mirror_unadjusted(&mut self, expr: &'tcx hir::Expr<'tcx>) -> Expr<'tcx>
                     lit: ScalarInt::try_from_uint(val, Size::from_bits(32)).unwrap(),
                     user_ty: None,
                 };
+                let mk_usize_kind = |val: u64| ExprKind::NonHirLiteral {
+                    lit: ScalarInt::try_from_uint(val, tcx.data_layout.pointer_size()).unwrap(),
+                    user_ty: None,
+                };
                 let mk_call =
                     |thir: &mut Thir<'tcx>, ty: Ty<'tcx>, variant: VariantIdx, field: FieldIdx| {
                         let fun_ty =
@@ -842,7 +846,7 @@ fn make_mirror_unadjusted(&mut self, expr: &'tcx hir::Expr<'tcx>) -> Expr<'tcx>
                     });
                 }
 
-                expr.unwrap_or(mk_u32_kind(0))
+                expr.unwrap_or_else(|| mk_usize_kind(0))
             }
 
             hir::ExprKind::ConstBlock(ref anon_const) => {