2 files changed, 19 insertions, 12 deletions
diff --git a/lib/active_relation/primitives/attribute.rb b/lib/active_relation/primitives/attribute.rb
index 4a10dffbe5..e55dd0bdc4 100644
--- a/lib/active_relation/primitives/attribute.rb
+++ b/lib/active_relation/primitives/attribute.rb
@@ -40,11 +40,27 @@ module ActiveRelation
       @alias      == other.alias     and
       ancestor    == other.ancestor
     end
-    alias_method :eql?, :==
     
-    def =~(other)
-      !(history & other.send(:history)).empty?
+    module Congruence
+      def self.included(klass)
+        klass.class_eval do
+          alias_method :eql?, :==
+        end
+      end
+      
+      def hash
+        relation.hash + name.hash
+      end
+      
+      def history
+        [self] + (ancestor ? [ancestor, ancestor.send(:history)].flatten : [])
+      end
+      
+      def =~(other)
+        !(history & other.send(:history)).empty?
+      end
     end
+    include Congruence
     
     module Predications
       def equals(other)
@@ -100,17 +116,9 @@ module ActiveRelation
       strategy.attribute prefix, name, self.alias
     end
     
-    def hash
-      relation.hash + name.hash
-    end
-    
     private
     def prefix
       relation.prefix_for(self)
     end
-    
-    def history
-      [self] + (ancestor ? [ancestor, ancestor.send(:history)].flatten : [])
-    end
   end
 end
 \ No newline at end of file
diff --git a/lib/active_relation/primitives/expression.rb b/lib/active_relation/primitives/expression.rb
index 4d28ef108c..35c1b5ff65 100644
--- a/lib/active_relation/primitives/expression.rb
+++ b/lib/active_relation/primitives/expression.rb
@@ -36,6 +36,5 @@ module ActiveRelation
       ancestor      == other.ancestor       and
       @alias        == other.alias
     end
-    alias_method :eql?, :==
   end
 end
 \ No newline at end of file