diff --git a/src/poly/utils/public/operator.h b/src/poly/utils/public/operator.h
index 56df44b..784f232 100644
--- a/src/poly/utils/public/operator.h
+++ b/src/poly/utils/public/operator.h
@@ -99,4 +99,5 @@ private:
 private:
     void updateInverseNonlinearJacobian(const mfem::Operator &grad) const;
     void updateInverseSchurCompliment() const;
+    void updatePreconditioner(const mfem::Operator &grad) const;
 };