diff --git a/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/GAB/FeatureGAB.cs b/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/GAB/FeatureGAB.cs
index e0eb9db..53b1922 100644
--- a/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/GAB/FeatureGAB.cs
+++ b/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/GAB/FeatureGAB.cs
@@ -118,6 +118,15 @@ namespace Acacia.Features.GAB
         }
         private static readonly BoolOption OPTION_PROCESS_MESSAGE = new BoolOption("ProcessMessage", true);
 
+        [AcaciaOption("If disabled, existing contacts are not deleted when a chunk is processed. " +
+                      "This should only be disabled for debug purposes.")]
+        public bool ProcessMessageDeleteExisting
+        {
+            get { return GetOption(OPTION_PROCESS_MESSAGE_DELETE_EXISTING); }
+            set { SetOption(OPTION_PROCESS_MESSAGE_DELETE_EXISTING, value); }
+        }
+        private static readonly BoolOption OPTION_PROCESS_MESSAGE_DELETE_EXISTING = new BoolOption("ProcessMessageDeleteExisting", true);
+
         [AcaciaOption("If disabled, contacts are not created from incoming GAB messages. " +
                       "This should only be disabled for debug purposes.")]
         public bool CreateContacts
diff --git a/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/GAB/GABHandler.cs b/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/GAB/GABHandler.cs
index f4af236..e2c67d6 100644
--- a/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/GAB/GABHandler.cs
+++ b/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/GAB/GABHandler.cs
@@ -268,18 +268,21 @@ namespace Acacia.Features.GAB
             _feature?.BeginProcessing();
             try
             {
-                // Delete the old contacts from this chunk
-                using (ISearch<IItem> search = Contacts.Search<IItem>())
+                if (_feature.ProcessMessageDeleteExisting)
                 {
-                    search.AddField(PROP_SEQUENCE, true).SetOperation(SearchOperation.Equal, index.numberOfChunks);
-                    search.AddField(PROP_CHUNK, true).SetOperation(SearchOperation.Equal, index.chunk);
-                    foreach (IItem oldItem in search.Search())
+                    // Delete the old contacts from this chunk
+                    using (ISearch<IItem> search = Contacts.Search<IItem>())
                     {
-                        // TODO: Search should handle this, like folder enumeration
-                        using (oldItem)
+                        search.AddField(PROP_SEQUENCE, true).SetOperation(SearchOperation.Equal, index.numberOfChunks);
+                        search.AddField(PROP_CHUNK, true).SetOperation(SearchOperation.Equal, index.chunk);
+                        foreach (IItem oldItem in search.Search())
                         {
-                            Logger.Instance.Trace(this, "Deleting GAB entry: {0}", oldItem.Subject);
-                            oldItem.Delete();
+                            // TODO: Search should handle this, like folder enumeration
+                            using (oldItem)
+                            {
+                                Logger.Instance.Trace(this, "Deleting GAB entry: {0}", oldItem.Subject);
+                                oldItem.Delete();
+                            }
                         }
                     }
                 }