1 files changed, 9 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb
index 1ca44d645c..96d0b73da2 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -124,6 +124,15 @@ module ActiveRecord
           column_name = "#{@reflection.quoted_table_name}.#{@reflection.klass.primary_key}" if column_name == :all
           options.merge!(:distinct => true) 
         end
+
+        if @reflection.options[:group]
+          unless column_name == :all
+            raise HasManyThroughCantCountOnColumnForGroupedAssociation.new(@owner, @reflection, column_name)
+          end
+          column_name = @reflection.options[:group]
+          options.merge!(:distinct => true)
+        end
+
         @reflection.klass.send(:with_scope, construct_scope) { @reflection.klass.count(column_name, options) } 
       end