diff --git a/app/models/query/results/sums.rb b/app/models/query/results/sums.rb
index 6da74e8cfba6..3eaf4dec7cca 100644
--- a/app/models/query/results/sums.rb
+++ b/app/models/query/results/sums.rb
@@ -42,7 +42,13 @@ def all_total_sums
   def all_group_sums
     return nil unless query.grouped?
 
-    sums_by_id = sums_select(true).inject({}) do |result, group_sum|
+    transform_group_keys(sums_by_group_id)
+  end
+
+  private
+
+  def sums_by_group_id
+    sums_select(true).inject({}) do |result, group_sum|
       result[group_sum["group_id"]] = {}
 
       query.summed_up_columns.each do |column|
@@ -51,12 +57,8 @@ def all_group_sums
 
       result
     end
-
-    transform_group_keys(sums_by_id)
   end
 
-  private
-
   def sums_select(grouped = false)
     select = if grouped
                ["work_packages.group_id"]