diff --git a/lib/redistat/summary.rb b/lib/redistat/summary.rb
index 23381ee..9ed4e05 100644
--- a/lib/redistat/summary.rb
+++ b/lib/redistat/summary.rb
@@ -3,11 +3,13 @@ module Redistat
     include Database
     extend Database
     
+    DEPTHS = [:year, :month, :day, :hour, :min, :sec, :usec]
+    
     def self.update_all(key, stats = {}, depth_limit = nil)
       stats ||= {}
       depth_limit ||= key.depth
       return nil if stats.size == 0
-      depths.each do |depth|
+      DEPTHS.each do |depth|
         update(key, stats, depth)
         break if depth == depth_limit
       end
@@ -21,9 +23,5 @@ module Redistat
       end
     end
     
-    def self.depths
-      [:year, :month, :day, :hour, :min, :sec, :usec]
-    end
-    
   end
 end
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