6 files changed, 34 insertions, 0 deletions
diff --git a/lib/arel/nodes/delete_statement.rb b/lib/arel/nodes/delete_statement.rb
index 54bf513c2b..b65177af05 100644
--- a/lib/arel/nodes/delete_statement.rb
+++ b/lib/arel/nodes/delete_statement.rb
@@ -7,6 +7,11 @@ module Arel
         @from   = nil
         @wheres = []
       end
+
+      def initialize_copy other
+        super
+        @wheres = @wheres.map { |o| o.clone }        
+      end
     end
   end
 end
diff --git a/lib/arel/nodes/insert_statement.rb b/lib/arel/nodes/insert_statement.rb
index ed601aa841..8c6e1234d0 100644
--- a/lib/arel/nodes/insert_statement.rb
+++ b/lib/arel/nodes/insert_statement.rb
@@ -8,6 +8,12 @@ module Arel
         @columns  = []
         @values   = []
       end
+
+      def initialize_copy other
+        super
+        @columns = @columns.map { |o| o.clone }
+        @values =  @values.map  { |o| o.clone }
+      end
     end
   end
 end
diff --git a/lib/arel/nodes/select_core.rb b/lib/arel/nodes/select_core.rb
index 39145de697..7ebdab315d 100644
--- a/lib/arel/nodes/select_core.rb
+++ b/lib/arel/nodes/select_core.rb
@@ -8,6 +8,13 @@ module Arel
         @projections = []
         @wheres      = []
       end
+
+      def initialize_copy other
+        super
+        @froms = @froms.map { |o| o.clone }
+        @projections = @projections.map { |o| o.clone }
+        @wheres = @wheres.map { |o| o.clone }
+      end
     end
   end
 end
diff --git a/lib/arel/nodes/select_statement.rb b/lib/arel/nodes/select_statement.rb
index 122f6275fe..50fef776f6 100644
--- a/lib/arel/nodes/select_statement.rb
+++ b/lib/arel/nodes/select_statement.rb
@@ -8,6 +8,11 @@ module Arel
         @cores = cores
         @limit = nil
       end
+
+      def initialize_copy other
+        super
+        @cores = @cores.map { |o| o.clone }
+      end
     end
   end
 end
diff --git a/lib/arel/nodes/update_statement.rb b/lib/arel/nodes/update_statement.rb
index 9f069cddb3..27e3e4e6ac 100644
--- a/lib/arel/nodes/update_statement.rb
+++ b/lib/arel/nodes/update_statement.rb
@@ -8,6 +8,12 @@ module Arel
         @wheres   = []
         @values   = []
       end
+
+      def initialize_copy other
+        super
+        @wheres = @wheres.map { |o| o.clone }
+        @values = @values.map { |o| o.clone }
+      end
     end
   end
 end
diff --git a/lib/arel/tree_manager.rb b/lib/arel/tree_manager.rb
index d2027bedfa..24df5e0c09 100644
--- a/lib/arel/tree_manager.rb
+++ b/lib/arel/tree_manager.rb
@@ -15,5 +15,10 @@ module Arel
       viz = Visitors::ToSql.new @engine
       viz.accept @head
     end
+
+    def initialize_copy other
+      super
+      @head = @head.clone
+    end
   end
 end