diff --git a/OpenRA.Mods.Common/Traits/Capturable.cs b/OpenRA.Mods.Common/Traits/Capturable.cs
index 27b4be205e..5108627d1b 100644
--- a/OpenRA.Mods.Common/Traits/Capturable.cs
+++ b/OpenRA.Mods.Common/Traits/Capturable.cs
@@ -17,8 +17,9 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("This actor can be captured by a unit with Captures: trait.")]
 	public class CapturableInfo : ConditionalTraitInfo, Requires<CaptureManagerInfo>
 	{
+		[FieldLoader.Require]
 		[Desc("CaptureTypes (from the Captures trait) that are able to capture this.")]
-		public readonly BitSet<CaptureType> Types = new BitSet<CaptureType>("building");
+		public readonly BitSet<CaptureType> Types = default(BitSet<CaptureType>);
 
 		[Desc("What diplomatic stances can be captured by this actor.")]
 		public readonly Stance ValidStances = Stance.Neutral | Stance.Enemy;
diff --git a/OpenRA.Mods.Common/Traits/Captures.cs b/OpenRA.Mods.Common/Traits/Captures.cs
index 40d13fde67..8950eddc63 100644
--- a/OpenRA.Mods.Common/Traits/Captures.cs
+++ b/OpenRA.Mods.Common/Traits/Captures.cs
@@ -22,8 +22,9 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("This actor can capture other actors which have the Capturable: trait.")]
 	public class CapturesInfo : ConditionalTraitInfo, Requires<CaptureManagerInfo>
 	{
+		[FieldLoader.Require]
 		[Desc("Types of actors that it can capture, as long as the type also exists in the Capturable Type: trait.")]
-		public readonly BitSet<CaptureType> CaptureTypes = new BitSet<CaptureType>("building");
+		public readonly BitSet<CaptureType> CaptureTypes = default(BitSet<CaptureType>);
 
 		[Desc("Targets with health above this percentage will be sabotaged instead of captured.",
 			"Set to 0 to disable sabotaging.")]