diff --git a/TimberWinR.ServiceHost/sampleconf.xml b/TimberWinR.ServiceHost/sampleconf.xml
index 39351ab..8d1d794 100644
--- a/TimberWinR.ServiceHost/sampleconf.xml
+++ b/TimberWinR.ServiceHost/sampleconf.xml
@@ -18,8 +18,7 @@
       <Match field="Text" value="%{SYSLOGLINE}" />               
     </Grok>
     <Mutate>
-      <Rename oldName="foo" newName="bar"/>
-      <Rename oldName="foo" newName="bar"/>
+      <Rename oldName="timestamp" newName="xtimestamp"/>    
     </Mutate>
     <Date field="timestamp" target="@timestamp" convertToUTC="true">
       <Pattern>MMM  d HH:mm:ss</Pattern>
diff --git a/TimberWinR/Configuration.cs b/TimberWinR/Configuration.cs
index e32274e..0afdc6d 100644
--- a/TimberWinR/Configuration.cs
+++ b/TimberWinR/Configuration.cs
@@ -474,9 +474,7 @@ namespace TimberWinR
 
             IEnumerable<XElement> filters =
                 from el in config.Root.Elements("Filters")
-                select el;
-
-            MutateFilter.Parse(_filters, config.Root);           
+                select el;                   
 
             foreach (XElement e in filters.Elements())
             {
@@ -487,7 +485,8 @@ namespace TimberWinR
                         GrokFilter grok = new GrokFilter(args);
                         _filters.Add(grok);
                         break;
-                    case "Mutate":
+                    case MutateFilter.TagName:
+                        MutateFilter.Parse(_filters, e);   
                         break;
                 }
             }
diff --git a/TimberWinR/Filters/MutateFilter.cs b/TimberWinR/Filters/MutateFilter.cs
index a1cf1b0..b58baf7 100644
--- a/TimberWinR/Filters/MutateFilter.cs
+++ b/TimberWinR/Filters/MutateFilter.cs
@@ -4,24 +4,22 @@ using System.IO;
 using System.Linq;
 using System.Text;
 using System.Xml.Linq;
+using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 
 namespace TimberWinR.Filters
 {
-    public class AddField
-    {
-        public string Target { get; set; }
-        public string Value { get; set; }
-    }
+   
 
     public class MutateFilter : FilterBase
     {
-        public List<Pair> Renames { get; set; }
+        public const string TagName = "Mutate";
 
-        public static void Parse(List<FilterBase> filters, XElement rootElement)
+        public List<Rename> Renames { get; private set; }
+
+        public static void Parse(List<FilterBase> filters, XElement mutateElement)
         {
-            foreach (var e in rootElement.Elements("Filters").Elements("Mutate"))
-                filters.Add(parseMutate(e));
+            filters.Add(parseMutate(mutateElement));
         }        
      
         static MutateFilter parseMutate(XElement e)
@@ -31,8 +29,7 @@ namespace TimberWinR.Filters
 
         MutateFilter(XElement parent)
         {
-            Renames = new List<Pair>();
-
+            Renames = new List<Rename>();
             ParseRenames(parent);
         }
 
@@ -40,14 +37,60 @@ namespace TimberWinR.Filters
         {
             foreach (var e in parent.Elements("Rename"))
             {
-                Pair p = new Pair(e.Attribute("oldName").Value, e.Attribute("newName").Value);
-                Renames.Add(p);
+                Rename r = new Rename(e.Attribute("oldName").Value, e.Attribute("newName").Value);
+                Renames.Add(r);
             }
         }
 
         public override void Apply(JObject json)
         {
-                     
-        }       
+            foreach (var r in Renames)
+                r.Apply(json);
+        }
+
+        public class Rename
+        {
+            public string OldName { get; set; }
+            public string NewName { get; set; }
+
+            public Rename(string oldName, string newName)
+            {
+                OldName = oldName;
+                NewName = newName;
+            }
+            public void Apply(JObject json)
+            {
+                json = RenameProperty(json, name => name == OldName ? NewName : name) as JObject;
+            }
+
+            private static JToken RenameProperty(JToken json, Dictionary<string, string> map)
+            {
+                return RenameProperty(json, name => map.ContainsKey(name) ? map[name] : name);
+            }
+
+            private static JToken RenameProperty(JToken json, Func<string, string> map)
+            {
+                JProperty prop = json as JProperty;
+                if (prop != null)
+                {
+                    return new JProperty(map(prop.Name), RenameProperty(prop.Value, map));
+                }
+
+                JArray arr = json as JArray;
+                if (arr != null)
+                {
+                    var cont = arr.Select(el => RenameProperty(el, map));
+                    return new JArray(cont);
+                }
+
+                JObject o = json as JObject;
+                if (o != null)
+                {
+                    var cont = o.Properties().Select(el => RenameProperty(el, map));
+                    return new JObject(cont);
+                }
+                return json;
+            }
+        }
     }
 }