diff --git a/mie/ir/op.c b/mie/ir/op.c
index b8aede7..88dd13b 100644
--- a/mie/ir/op.c
+++ b/mie/ir/op.c
@@ -108,6 +108,10 @@ struct mie_op_successor *mie_op_add_successor(
 
 static bool is_isolated(const struct mie_op *op)
 {
+	if (!(op->op_flags & MIE_OP_F_OP_RESOLVED)) {
+		return false;
+	}
+
 	const struct mie_trait *isolated = mie_trait_table_get_unique(
 		&op->op_info->op_traits, "builtin", "isolated-from-above");
 	return isolated != NULL;