diff --git a/lib/table_print/config.rb b/lib/table_print/config.rb
index b9f385e..79e1068 100644
--- a/lib/table_print/config.rb
+++ b/lib/table_print/config.rb
@@ -25,7 +25,14 @@ def self.set(klass, val)
     end
 
     def self.for(klass)
-      @@klasses.fetch(klass) {}
+      config = @@klasses.fetch(klass) {}
+      if config.is_a?(Array)
+        config.map { |c| c.is_a?(Hash) ? c.dup : c }
+      elsif config.is_a?(Hash)
+        config.dup
+      else
+        config    
+      end
     end
 
     def self.clear(klass)
diff --git a/spec/config_spec.rb b/spec/config_spec.rb
index 5a09932..b3550b4 100644
--- a/spec/config_spec.rb
+++ b/spec/config_spec.rb
@@ -37,6 +37,12 @@
         TablePrint::Config.set(Sandbox::Blog, [:title, :author])
         TablePrint::Config.for(Sandbox::Blog).should == [:title, :author]
       end
+
+      it "makes a copy on retrieval" do |variable|
+        TablePrint::Config.set(Sandbox::Blog, [:title, :author])
+        TablePrint::Config.for(Sandbox::Blog).clear
+        TablePrint::Config.for(Sandbox::Blog).should == [:title, :author]
+      end
     end
 
     describe "clearing" do