diff --git a/openmc/mgxs/mgxs.py b/openmc/mgxs/mgxs.py
index 11b2b24ed..01a03f650 100644
--- a/openmc/mgxs/mgxs.py
+++ b/openmc/mgxs/mgxs.py
@@ -3926,7 +3926,7 @@ class ScatterMatrixXS(MatrixMGXS):
                         # to match scattering matrix shape for tally arithmetic
                         energy_filter = copy.deepcopy(energy_filter)
                         scatter_p1 = \
-                            scatter_p1.diagonalize_filter(energy_filter)
+                            scatter_p1.diagonalize_filter(energy_filter, 1)
 
                         self._rxn_rate_tally = scatter_p0 - scatter_p1
 
@@ -4022,7 +4022,7 @@ class ScatterMatrixXS(MatrixMGXS):
                     # to match scattering matrix shape for tally arithmetic
                     energy_filter = flux.find_filter(openmc.EnergyFilter)
                     energy_filter = copy.deepcopy(energy_filter)
-                    scatter_p1 = scatter_p1.diagonalize_filter(energy_filter)
+                    scatter_p1 = scatter_p1.diagonalize_filter(energy_filter, 1)
 
                     # Compute the trasnport correction term
                     correction = scatter_p1 / flux
diff --git a/openmc/tallies.py b/openmc/tallies.py
index a5f3a17f3..18c359c46 100644
--- a/openmc/tallies.py
+++ b/openmc/tallies.py
@@ -2964,7 +2964,7 @@ class Tally(IDManagerMixin):
         tally_avg.sparse = self.sparse
         return tally_avg
 
-    def diagonalize_filter(self, new_filter):
+    def diagonalize_filter(self, new_filter, filter_position=-1):
         """Diagonalize the tally data array along a new axis of filter bins.
 
         This is a helper method for the tally arithmetic methods. This method
@@ -2979,6 +2979,9 @@ class Tally(IDManagerMixin):
         ----------
         new_filter : Filter
             The filter along which to diagonalize the data in the new
+        filter_position : int
+            Where to place the new filter in the Tally.filters list. Defaults
+            to last position.
 
         Returns
         -------
@@ -2988,6 +2991,7 @@ class Tally(IDManagerMixin):
         """
 
         cv.check_type('new_filter', new_filter, _FILTER_CLASSES)
+        cv.check_type('filter_position', filter_position, Integral)
 
         if new_filter in self.filters:
             msg = 'Unable to diagonalize Tally ID="{0}" which already ' \
@@ -2996,7 +3000,7 @@ class Tally(IDManagerMixin):
 
         # Add the new filter to a copy of this Tally
         new_tally = copy.deepcopy(self)
-        new_tally.filters.append(new_filter)
+        new_tally.filters.insert(filter_position, new_filter)
 
         # Determine "base" indices along the new "diagonal", and the factor
         # by which the "base" indices should be repeated to account for all