diff --git a/src/Dets/utils.irp.f b/src/Dets/utils.irp.f
index 0ead6090..0b89f339 100644
--- a/src/Dets/utils.irp.f
+++ b/src/Dets/utils.irp.f
@@ -14,36 +14,3 @@ BEGIN_PROVIDER [ double precision, H_matrix_all_dets,(N_det,N_det) ]
  enddo
 END_PROVIDER
 
-subroutine remove_small_contributions
-  implicit none
-  BEGIN_DOC
-!  Remove determinants with small contributions
-  END_DOC
-  integer :: i,j,k, N_removed
-  logical keep
-  N_removed = 0
-  do i=N_det,1,-1
-    keep = .False.
-    do j=1,N_states
-      keep = keep .or. (dabs(psi_coef(i,j)) > selection_criterion_min)
-    enddo
-    if (.not.keep) then
-      do k=i+1,N_det
-        do j=1,N_int
-           psi_det(j,1,k-1) = psi_det(j,1,k)
-           psi_det(j,2,k-1) = psi_det(j,2,k)
-        enddo
-      enddo
-      do j=1,N_states
-        do k=i+1,N_det
-           psi_coef(k-1,j) = psi_coef(k,j)
-        enddo
-      enddo
-      N_removed += 1
-    endif
-  enddo
-  if (N_removed > 0) then
-    N_det -= N_removed
-    call write_int(output_dets,N_removed, 'Removed determinants')
-  endif
-end
diff --git a/src/Perturbation/README.rst b/src/Perturbation/README.rst
index 0407fc2c..1b0f8697 100644
--- a/src/Perturbation/README.rst
+++ b/src/Perturbation/README.rst
@@ -188,6 +188,9 @@ Documentation
 `fill_h_apply_buffer_selection <http://github.com/LCPQ/quantum_package/tree/master/src/Perturbation/selection.irp.f#L1>`_
   Fill the H_apply buffer with determiants for the selection
 
+`remove_small_contributions <http://github.com/LCPQ/quantum_package/tree/master/src/Perturbation/selection.irp.f#L80>`_
+  Remove determinants with small contributions
+
 `selection_criterion <http://github.com/LCPQ/quantum_package/tree/master/src/Perturbation/selection.irp.f#L67>`_
   Threshold to select determinants. Set by selection routines.
 
diff --git a/src/Perturbation/selection.irp.f b/src/Perturbation/selection.irp.f
index 60e8a1ee..14d452cb 100644
--- a/src/Perturbation/selection.irp.f
+++ b/src/Perturbation/selection.irp.f
@@ -77,3 +77,36 @@ end
 
 END_PROVIDER
 
+subroutine remove_small_contributions
+  implicit none
+  BEGIN_DOC
+!  Remove determinants with small contributions
+  END_DOC
+  integer :: i,j,k, N_removed
+  logical keep
+  N_removed = 0
+  do i=N_det,1,-1
+    keep = .False.
+    do j=1,N_states
+      keep = keep .or. (dabs(psi_coef(i,j)) > selection_criterion_min)
+    enddo
+    if (.not.keep) then
+      do k=i+1,N_det
+        do j=1,N_int
+           psi_det(j,1,k-1) = psi_det(j,1,k)
+           psi_det(j,2,k-1) = psi_det(j,2,k)
+        enddo
+      enddo
+      do j=1,N_states
+        do k=i+1,N_det
+           psi_coef(k-1,j) = psi_coef(k,j)
+        enddo
+      enddo
+      N_removed += 1
+    endif
+  enddo
+  if (N_removed > 0) then
+    N_det -= N_removed
+    call write_int(output_dets,N_removed, 'Removed determinants')
+  endif
+end