1 files changed, 4 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb
index 55bf2e0ff0..d35fe9fe50 100644
--- a/activerecord/lib/active_record/associations/collection_proxy.rb
+++ b/activerecord/lib/active_record/associations/collection_proxy.rb
@@ -33,6 +33,10 @@ module ActiveRecord
         super klass, klass.arel_table, klass.predicate_builder
       end
 
+      def initialize_dup(other) # :nodoc:
+        @association = @association.deep_dup
+      end
+
       def target
         @association.target
       end