diff --git a/OpenRA.Mods.Common/AI/HackyAI.cs b/OpenRA.Mods.Common/AI/HackyAI.cs
index 7b73031655..795692ba97 100644
--- a/OpenRA.Mods.Common/AI/HackyAI.cs
+++ b/OpenRA.Mods.Common/AI/HackyAI.cs
@@ -1108,7 +1108,7 @@ namespace OpenRA.Mods.Common.AI
 				QueueOrder(Order.StartProduction(queue.Actor, name, 1));
 		}
 
-		public void Damaged(Actor self, AttackInfo e)
+		void INotifyDamage.Damaged(Actor self, AttackInfo e)
 		{
 			if (!IsEnabled || e.Attacker == null)
 				return;
diff --git a/OpenRA.Mods.Common/Scripting/ScriptTriggers.cs b/OpenRA.Mods.Common/Scripting/ScriptTriggers.cs
index 70706590d1..9fbfd872d0 100644
--- a/OpenRA.Mods.Common/Scripting/ScriptTriggers.cs
+++ b/OpenRA.Mods.Common/Scripting/ScriptTriggers.cs
@@ -107,7 +107,7 @@ namespace OpenRA.Mods.Common.Scripting
 			}
 		}
 
-		public void Damaged(Actor self, AttackInfo e)
+		void INotifyDamage.Damaged(Actor self, AttackInfo e)
 		{
 			if (world.Disposing)
 				return;
diff --git a/OpenRA.Mods.Common/Traits/Player/BaseAttackNotifier.cs b/OpenRA.Mods.Common/Traits/Player/BaseAttackNotifier.cs
index 9efb152d6e..63213bce71 100644
--- a/OpenRA.Mods.Common/Traits/Player/BaseAttackNotifier.cs
+++ b/OpenRA.Mods.Common/Traits/Player/BaseAttackNotifier.cs
@@ -50,7 +50,7 @@ namespace OpenRA.Mods.Common.Traits
 			lastAttackTime = -info.NotifyInterval * 25;
 		}
 
-		public void Damaged(Actor self, AttackInfo e)
+		void INotifyDamage.Damaged(Actor self, AttackInfo e)
 		{
 			if (e.Attacker == null)
 				return;
diff --git a/OpenRA.Mods.Common/Traits/Player/HarvesterAttackNotifier.cs b/OpenRA.Mods.Common/Traits/Player/HarvesterAttackNotifier.cs
index 69a85ac36f..1597b54464 100644
--- a/OpenRA.Mods.Common/Traits/Player/HarvesterAttackNotifier.cs
+++ b/OpenRA.Mods.Common/Traits/Player/HarvesterAttackNotifier.cs
@@ -46,7 +46,7 @@ namespace OpenRA.Mods.Common.Traits
 			lastAttackTime = -info.NotifyInterval * 25;
 		}
 
-		public void Damaged(Actor self, AttackInfo e)
+		void INotifyDamage.Damaged(Actor self, AttackInfo e)
 		{
 			// Don't track self-damage
 			if (e.Attacker != null && e.Attacker.Owner == self.Owner)
diff --git a/OpenRA.Mods.Common/Traits/Render/WithDamageOverlay.cs b/OpenRA.Mods.Common/Traits/Render/WithDamageOverlay.cs
index 031ff86caf..bd1ec869a3 100644
--- a/OpenRA.Mods.Common/Traits/Render/WithDamageOverlay.cs
+++ b/OpenRA.Mods.Common/Traits/Render/WithDamageOverlay.cs
@@ -53,7 +53,7 @@ namespace OpenRA.Mods.Common.Traits.Render
 			rs.Add(new AnimationWithOffset(anim, null, () => !isSmoking));
 		}
 
-		public void Damaged(Actor self, AttackInfo e)
+		void INotifyDamage.Damaged(Actor self, AttackInfo e)
 		{
 			if (info.DamageTypes.Count > 0 && !e.Damage.DamageTypes.Overlaps(info.DamageTypes))
 				return;
diff --git a/OpenRA.Mods.Common/Traits/SelfHealing.cs b/OpenRA.Mods.Common/Traits/SelfHealing.cs
index 59e377b658..36022ca4db 100644
--- a/OpenRA.Mods.Common/Traits/SelfHealing.cs
+++ b/OpenRA.Mods.Common/Traits/SelfHealing.cs
@@ -74,7 +74,7 @@ namespace OpenRA.Mods.Common.Traits
 			}
 		}
 
-		public void Damaged(Actor self, AttackInfo e)
+		void INotifyDamage.Damaged(Actor self, AttackInfo e)
 		{
 			if (e.Damage.Value > 0)
 				damageTicks = Info.DamageCooldown;
diff --git a/OpenRA.Mods.Common/TraitsInterfaces.cs b/OpenRA.Mods.Common/TraitsInterfaces.cs
index 90a9e10a9a..d1ca0ef513 100644
--- a/OpenRA.Mods.Common/TraitsInterfaces.cs
+++ b/OpenRA.Mods.Common/TraitsInterfaces.cs
@@ -83,6 +83,7 @@ namespace OpenRA.Mods.Common.Traits
 	[RequireExplicitImplementation]
 	public interface INotifyDamageStateChanged { void DamageStateChanged(Actor self, AttackInfo e); }
 
+	[RequireExplicitImplementation]
 	public interface INotifyDamage { void Damaged(Actor self, AttackInfo e); }
 	public interface INotifyKilled { void Killed(Actor self, AttackInfo e); }
 	public interface INotifyAppliedDamage { void AppliedDamage(Actor self, Actor damaged, AttackInfo e); }