diff --git a/src/cipsi/cipsi.irp.f b/src/cipsi/cipsi.irp.f
index 5b0b00c0..413a9d9a 100644
--- a/src/cipsi/cipsi.irp.f
+++ b/src/cipsi/cipsi.irp.f
@@ -88,7 +88,7 @@ subroutine run_cipsi
       threshold_generators = threshold_generators_save
       SOFT_TOUCH threshold_generators
     else
-    call ZMQ_selection(to_select, pt2, variance, norm)
+      call ZMQ_selection(to_select, pt2, variance, norm)
     endif
 
     do k=1,N_states
diff --git a/src/cipsi/run_selection_slave.irp.f b/src/cipsi/run_selection_slave.irp.f
index f031bc72..fe712c45 100644
--- a/src/cipsi/run_selection_slave.irp.f
+++ b/src/cipsi/run_selection_slave.irp.f
@@ -59,8 +59,7 @@ subroutine run_selection_slave(thread,iproc,energy)
       read(task,*) subset, i_generator, N
       if(buf%N == 0) then
         ! Only first time
-        bsize = min(N, (elec_alpha_num * (mo_num-elec_alpha_num))**2)
-        call create_selection_buffer(bsize, bsize*2, buf)
+        call create_selection_buffer(N, N*2, buf)
         buffer_ready = .True.
       else
         if (N /= buf%N) then
diff --git a/src/cipsi/zmq_selection.irp.f b/src/cipsi/zmq_selection.irp.f
index a6f26ed8..c0545aa1 100644
--- a/src/cipsi/zmq_selection.irp.f
+++ b/src/cipsi/zmq_selection.irp.f
@@ -16,6 +16,7 @@ subroutine ZMQ_selection(N_in, pt2, variance, norm)
 !  PROVIDE psi_det psi_coef N_det qp_max_mem N_states pt2_F s2_eig N_det_generators
 
   N = max(N_in,1)
+  N = min(N, (elec_alpha_num * (mo_num-elec_alpha_num))**2)
   if (.True.) then
     PROVIDE pt2_e0_denominator nproc
     PROVIDE psi_bilinear_matrix_columns_loc psi_det_alpha_unique psi_det_beta_unique
@@ -78,6 +79,7 @@ subroutine ZMQ_selection(N_in, pt2, variance, norm)
       stop 'Unable to add task to task server'
     endif
   endif
+  N = max(N_in,1)
 
 
   ASSERT (associated(b%det))