diff --git a/bindings/python/requirements.txt b/bindings/python/requirements.txt
index a992b42b..79d955ec 100644
--- a/bindings/python/requirements.txt
+++ b/bindings/python/requirements.txt
@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.10
 # by the following command:
 #
-#    pip-compile bindings/python/requirements.in
+#    pip-compile --pre bindings/python/requirements.in
 #
 opengeode-core==14.*,>=14.17.0
     # via -r bindings/python/requirements.in
diff --git a/src/geode/geosciences/implicit/representation/core/detail/helpers.cpp b/src/geode/geosciences/implicit/representation/core/detail/helpers.cpp
index 7b44bdd4..9dfe9308 100644
--- a/src/geode/geosciences/implicit/representation/core/detail/helpers.cpp
+++ b/src/geode/geosciences/implicit/representation/core/detail/helpers.cpp
@@ -57,11 +57,11 @@ namespace
     void check_number_of_horizons_and_stratigraphic_units(
         geode::index_t nb_horizons, geode::index_t nb_units )
     {
-        OPENGEODE_EXCEPTION( nb_horizons < nb_units + 2,
+        OPENGEODE_EXCEPTION( nb_horizons <= nb_units + 1,
             "[repair_horizon_stack_if_possible] Too many horizons compared "
             "to stratigraphic units (",
             nb_horizons, ", should be less than ", nb_units, ")" );
-        OPENGEODE_EXCEPTION( nb_units < nb_horizons + 2,
+        OPENGEODE_EXCEPTION( nb_units <= nb_horizons + 1,
             "[repair_horizon_stack_if_possible] Too many stratigraphic "
             "units compared to horizons (",
             nb_units, ", should be less than ", nb_horizons, ")" );
@@ -304,8 +304,9 @@ namespace geode
             for( const auto counter : Range{ 1, horizons_names.size() } )
             {
                 const auto& su_above = builder.add_stratigraphic_unit();
-                builder.set_stratigraphic_unit_name( su_above,
-                    units_names[counter + lowest_unit_to_create ? -1 : 0] );
+                builder.set_stratigraphic_unit_name(
+                    su_above, units_names[lowest_unit_to_create ? counter - 1
+                                                                : counter] );
                 builder.add_horizon_under( stack.horizon( current_horizon ),
                     stack.stratigraphic_unit( su_above ) );
                 current_horizon = builder.add_horizon();