diff --git a/src/Hartree_Fock/diagonalize_fock.irp.f b/src/Hartree_Fock/diagonalize_fock.irp.f
index 1efd8376..00f3275b 100644
--- a/src/Hartree_Fock/diagonalize_fock.irp.f
+++ b/src/Hartree_Fock/diagonalize_fock.irp.f
@@ -4,11 +4,11 @@ subroutine diagonalize_fock()
   double precision, allocatable :: mo_coef_new(:,:), R(:,:),eigvalues(:)
   !DIR$ ATTRIBUTES ALIGN : $IRP_ALIGN ::  mo_coef_new, R
 
-  allocate(R(mo_tot_num,mo_tot_num))
+  allocate(R(size(Fock_matrix_mo,1),mo_tot_num))
   allocate(mo_coef_new(ao_num_align,mo_tot_num),eigvalues(mo_tot_num))
   mo_coef_new = mo_coef
 
-  call lapack_diag(eigvalues,R,Fock_matrix_mo,mo_tot_num,mo_tot_num)
+  call lapack_diag(eigvalues,R,Fock_matrix_mo,size(Fock_matrix_mo,1),mo_tot_num)
 
   call dgemm('N','N',ao_num,mo_tot_num,mo_tot_num,1.d0,mo_coef_new,size(mo_coef_new,1),R,size(R,1),0.d0,mo_coef,size(mo_coef,1))
   deallocate(mo_coef_new,R,eigvalues)