diff --git a/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj b/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
index e2e9160f54..a291e8038f 100644
--- a/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
+++ b/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
@@ -593,6 +593,7 @@
     <Compile Include="UpdateRules\Rules\20180923\MergeCaptureTraits.cs" />
     <Compile Include="UpdateRules\Rules\20180923\RemovedNotifyBuildComplete.cs" />
     <Compile Include="UpdateRules\Rules\20180923\ChangeTakeOffSoundAndLandingSound.cs" />
+    <Compile Include="UpdateRules\Rules\20180923\AddCarryableHarvester.cs" />
     <Compile Include="UtilityCommands\CheckYaml.cs" />
     <Compile Include="UtilityCommands\ConvertPngToShpCommand.cs" />
     <Compile Include="UtilityCommands\ConvertSpriteToPngCommand.cs" />
diff --git a/OpenRA.Mods.Common/UpdateRules/Rules/20180923/AddCarryableHarvester.cs b/OpenRA.Mods.Common/UpdateRules/Rules/20180923/AddCarryableHarvester.cs
new file mode 100644
index 0000000000..a137f26f95
--- /dev/null
+++ b/OpenRA.Mods.Common/UpdateRules/Rules/20180923/AddCarryableHarvester.cs
@@ -0,0 +1,61 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2018 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace OpenRA.Mods.Common.UpdateRules.Rules
+{
+	public class AddCarryableHarvester : UpdateRule
+	{
+		public override string Name { get { return "Inform about the 'CarryableHarvester' trait."; } }
+		public override string Description
+		{
+			get
+			{
+				return "A 'CarryableHarvester' trait was added for harvesters that use 'AutoCarryable'.";
+			}
+		}
+
+		bool hasAutoCarryable;
+		readonly List<string> harvesters = new List<string>();
+
+		public override IEnumerable<string> BeforeUpdate(ModData modData)
+		{
+			harvesters.Clear();
+			yield break;
+		}
+
+		public override IEnumerable<string> UpdateActorNode(ModData modData, MiniYamlNode actorNode)
+		{
+			if (!hasAutoCarryable)
+				hasAutoCarryable = actorNode.ChildrenMatching("AutoCarryable").Any();
+
+			var harvester = actorNode.LastChildMatching("Harvester");
+			if (harvester != null)
+				harvesters.Add("{0} ({1})".F(actorNode.Key, harvester.Location.Filename));
+
+			yield break;
+		}
+
+		public override IEnumerable<string> AfterUpdate(ModData modData)
+		{
+			if (!hasAutoCarryable || !harvesters.Any())
+				yield break;
+
+			yield return "Detected an 'AutoCarryable' trait.\n" +
+				"Review the following definitions and, if required,\n" +
+				"add the new 'CarryableHarvester' trait.\n" +
+					UpdateUtils.FormatMessageList(harvesters, 1);
+		}
+	}
+}
diff --git a/OpenRA.Mods.Common/UpdateRules/UpdatePath.cs b/OpenRA.Mods.Common/UpdateRules/UpdatePath.cs
index d598972074..df9351b022 100644
--- a/OpenRA.Mods.Common/UpdateRules/UpdatePath.cs
+++ b/OpenRA.Mods.Common/UpdateRules/UpdatePath.cs
@@ -89,6 +89,7 @@ namespace OpenRA.Mods.Common.UpdateRules
 			new UpdatePath("release-20180923", new UpdateRule[]
 			{
 				// Bleed only changes here
+				new AddCarryableHarvester(),
 				new RenameEditorTilesetFilter(),
 				new DefineNotificationDefaults(),
 				new MergeRearmAndRepairAnimation(),