diff --git a/src/Dets/connected_to_ref.irp.f b/src/Dets/connected_to_ref.irp.f
index fd87cc3c..1b9e0c35 100644
--- a/src/Dets/connected_to_ref.irp.f
+++ b/src/Dets/connected_to_ref.irp.f
@@ -60,6 +60,7 @@ integer function get_index_in_psi_det_sorted_bit(key,Nint)
   integer*8, external            :: det_search_key
   logical                        :: is_in_wavefunction
   
+  is_in_wavefunction = .False.
   get_index_in_psi_det_sorted_bit = 0
   ibegin = 1
   iend   = N_det+1
diff --git a/src/Perturbation/perturbation_template.f b/src/Perturbation/perturbation_template.f
index 3627dd17..e289d409 100644
--- a/src/Perturbation/perturbation_template.f
+++ b/src/Perturbation/perturbation_template.f
@@ -25,7 +25,7 @@ subroutine perturb_buffer_$PERT(i_generator,buffer,buffer_size,e_2_pert_buffer,c
   ASSERT (N_st > 0)
   do i = 1,buffer_size
 
-    c_ref = connected_to_ref(buffer(1,1,i),psi_generators,Nint,i_generator,N_det)
+    c_ref = connected_to_ref(buffer(1,1,i),psi_generators,Nint,i_generator,N_det_generators)
 
     if (c_ref /= 0) then
       cycle