diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 3c05c52..c52e58e 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -1472,7 +1472,8 @@ module ActiveRecord
           # Only join tables referenced in order or conditions since this is particularly slow on the pre-query.
           tables_from_conditions = conditions_tables(options)
           tables_from_order      = order_tables(options)
-          all_tables             = tables_from_conditions + tables_from_order
+          tables_from_group      = group_tables(options)
+          all_tables             = tables_from_conditions + tables_from_order + tables_from_group
           distinct_join_associations = all_tables.uniq.map{|table|
             join_dependency.joins_for_table_name(table)
           }.flatten.compact.uniq
@@ -1482,7 +1483,7 @@ module ActiveRecord
             order = order ? "#{order}, #{scoped_order}" : scoped_order
           end
 
-          is_distinct = !options[:joins].blank? || include_eager_conditions?(options, tables_from_conditions) || include_eager_order?(options, tables_from_order)
+          is_distinct = !options[:joins].blank? || include_eager_conditions?(options, tables_from_conditions) || include_eager_order?(options, tables_from_order) || include_eager_group?(options, tables_from_group)
           sql = "SELECT "
           if is_distinct
             sql << connection.distinct("#{connection.quote_table_name table_name}.#{primary_key}", order)
@@ -1534,6 +1535,12 @@ module ActiveRecord
           select.scan(/"?([\.a-zA-Z_]+)"?.?\./).flatten
         end
 
+        def group_tables(options)
+          group = [options[:group], scope(:find, :group) ].join(", ")
+          return [] unless group && group.is_a?(String)
+          group.scan(/([\.a-zA-Z_]+).?\./).flatten
+        end
+
         # Checks if the conditions reference a table other than the current model table
         def include_eager_conditions?(options, tables = nil)
           ((tables || conditions_tables(options)) - [table_name]).any?
@@ -1544,12 +1551,17 @@ module ActiveRecord
           ((tables || order_tables(options)) - [table_name]).any?
         end
 
+        # Checks if the query group references a table other than the current model's table.
+        def include_eager_group?(options, tables = nil)
+          ((tables || group_tables(options)) - [table_name]).any?
+        end
+
         def include_eager_select?(options)
           (selects_tables(options) - [table_name]).any?
         end
 
         def references_eager_loaded_tables?(options)
-          include_eager_order?(options) || include_eager_conditions?(options) || include_eager_select?(options)
+          include_eager_order?(options) || include_eager_conditions?(options) || include_eager_select?(options) || include_eager_group?(options)
         end
 
         def using_limitable_reflections?(reflections)
diff --git a/activerecord/test/cases/associations/eager_test.rb b/activerecord/test/cases/associations/eager_test.rb
index 6fec290..0809a49 100644
--- a/activerecord/test/cases/associations/eager_test.rb
+++ b/activerecord/test/cases/associations/eager_test.rb
@@ -640,4 +640,8 @@ class EagerAssociationTest < ActiveRecord::TestCase
   def test_order_on_join_table_with_include_and_limit
     assert_equal 5, Developer.find(:all, :include => 'projects', :order => 'developers_projects.joined_on DESC', :limit => 5).size
   end
+
+  def test_group_on_join_table_with_include_and_limit
+    assert_equal 2, Developer.find(:all, :include => 'projects', :group => 'projects.name', :limit => 5).size
+  end
 end