diff --git a/lib/gitlab/background_migration/migrate_stage_index.rb b/lib/gitlab/background_migration/migrate_stage_index.rb
index f90f35a913d..f921233460d 100644
--- a/lib/gitlab/background_migration/migrate_stage_index.rb
+++ b/lib/gitlab/background_migration/migrate_stage_index.rb
@@ -21,8 +21,8 @@ module Gitlab
                   AND stage_idx IS NOT NULL
                 GROUP BY stage_id, stage_idx
             ), indexes AS (
-              SELECT DISTINCT stage_id, last_value(stage_idx)
-                OVER (PARTITION BY stage_id ORDER BY freq ASC) AS index
+              SELECT DISTINCT stage_id, first_value(stage_idx)
+                OVER (PARTITION BY stage_id ORDER BY freq DESC) AS index
                 FROM freqs
             )
 
diff --git a/spec/lib/gitlab/background_migration/migrate_stage_index_spec.rb b/spec/lib/gitlab/background_migration/migrate_stage_index_spec.rb
index f8107dd40b9..4db829b1e7b 100644
--- a/spec/lib/gitlab/background_migration/migrate_stage_index_spec.rb
+++ b/spec/lib/gitlab/background_migration/migrate_stage_index_spec.rb
@@ -30,6 +30,6 @@ describe Gitlab::BackgroundMigration::MigrateStageIndex, :migration, schema: 201
 
     described_class.new.perform(100, 101)
 
-    expect(stages.all.pluck(:position)).to eq [2, 3]
+    expect(stages.all.order(:id).pluck(:position)).to eq [2, 3]
   end
 end